Electronic mail communication system

ABSTRACT

An electronic mail communication system or the like capable of transmitting and receiving electronic mail to and from a target who does not have a membership registration without disclosure of a personal electronic mail address and also easy in controlling acceptance or rejection of mail. Where the received electronic mail is determined to be target addressed mail, the decode means  17  of the mail server device  4  writes a target actual address as a field value of a destination header, without changing a text thereof, thereby generating target addressed transfer mail in which a connection address is written as a field value of the source header. Where the received electronic mail is determined to be the user addressed mail, the encode means  14  generates user addressed transfer mail in which the user actual address is written as a field value of the destination header without changing the text.

CROSS REFERENCE OF RELATED APPLICATIONS

The disclosure of Japanese Patent Applications No. 2013-098224 (filed May 8, 2013) and No. 2013-236940 (filed Nov. 15, 2013) including the specification, claims, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an electronic mail communication system and, in particular, to a technology which enables electronic mail communications without disclosing a personal electronic mail address.

2. Background Art

In order to make available a service offered via the Internet such as Internet shopping, there is often found such a case that registration of a personal electronic mail address (may be, hereinafter, simply referred to as “mail address”) is required at a site which offers the service.

However, once the mail address has been registered, there is found such a case that unwanted advertisement mail is thereafter transmitted to this mail address. Further, there is a possibility that personal behavior on the Internet may be tracked and analyzed based on the mail address and information thereof may be provided to third parties. In this case, unsolicited bulk electronic mail such as advertisement mail is transmitted more frequently.

In order to avoid the above described situation, it may be possible to change the mail address. However, a mail address is often used for other purposes. Thus, in most cases, it is actually impossible to change a mail address.

Therefore, such a system has been proposed that on registration of membership, a client-specific special mail address is allocated to a client. Thereafter, where the client exchanges information with other clients via electronic mail or tries to find a target for exchanging information, a personal carrier mail address is automatically converted to the client-specific special mail address and mail is then transmitted to a designated recipient or the special mail address is made public on a website or others (refer to FIG. 3 to FIG. 5 in Patent Document 1).

According to this system, since the carrier mail address of the client is not made public, it is possible to eliminate harassment such as tampering and annoyance and also to realize a safe and brief exchange of information with many people via electronic mail.

However, in the above described system, both a sender and a recipient are assumed to have membership registration. Thus, this system is not usable on transmission and receiving of electronic mail to and from a target who does not have a membership registration.

Further, a personal client-specific special mail address is provided by one. Thus, where receiving of a message from an unwanted target is rejected, a member is to personally identify the target, thereby setting rejection of receiving of the message. Where information is exchanged with multiple targets, in particular, after the personal client-specific special mail address has been made public on a website or the like, operation for controlling acceptance or rejection of mail will be quite troublesome and complicated.

Patent Document 1

-   Japanese Unexamined Patent Application Publication No. 2002-123470

DISCLOSURE OF THE INVENTION

The present invention is to provide an electronic mail communication system etc., which solves the above described conventional problem, enables the transmission and receiving of electronic mail with a target who does not have a membership registration without disclosure of a personal electronic mail address and which is also easy in controlling receiving or rejection of the electronic mail.

The electronic mail communication system of the present invention is an electronic mail communication system which is provided with a plurality of mail transmitting/receiving devices, each of which has a mail processing portion with functions to transmit and receive electronic mail, and a mail server device which is able to communicate with the mail transmitting/receiving device via information communication means. The mail server device is provided with a database which stores a target actual address which is an electronic mail address of a target to which electronic mail is transmitted and a user actual address which is an electronic mail address of a registered user for receiving the electronic mail replied by the target in association with a connection identification indicator corresponding to a connection address which is a temporary electronic mail address of the registered user and an electronic mail address under control of the mail server device, and a transfer processing portion which executes transfer and processing of the electronic mail based on data stored in the database. The transfer processing portion is provided with mail receiving means which receives electronic mail from the mail transmitting/receiving device via the information communication means, mail determination means which determines whether or not the electronic mail received by the mail receiving means is target addressed mail which is to be transmitted from a registered user to a target or user addressed mail which is to be transmitted to the registered user from the target based on header information of the electronic mail, decode means which generates target addressed transfer mail which is electronic mail in which a field value of a destination header indicating a destination of the target addressed mail is given as a target actual address and a field value of a source header indicating a source is given as a connection address corresponding to a connection identification indicator where the mail determination means determines that the electronic mail is the target addressed mail, encode means which generates user addressed transfer mail in which a field value of a destination header of the user addressed mail is given as a user actual address where the mail determination means determines that the electronic mail is the user addressed mail, that is, user addressed transfer mail which is given as target addressed mail if replied after a text of the user addressed transfer mail is rewritten by the mail transmitting/receiving device which has received the user addressed transfer mail, and mail transmitting means which transmits electronic mail generated by the decode means or the encode means via the information communication means in accordance with the header information of the electronic mail.

Features of the present invention can be widely shown as described above. Arrangements and content thereof, together with an object and features, will be further clarified by the following disclosure, with drawings taken into account.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram which shows an arrangement of an electronic mail communication system 2 according to one embodiment of the present invention.

FIG. 2 is a block diagram which illustrates an arrangement of a mail server device 4.

FIG. 3 is a block diagram which illustrates an arrangement of a mail transmitting/receiving device 6.

FIG. 4 is a block diagram which shows one example of a hardware arrangement covering the mail server device 4 in FIG. 2 and the mail transmitting/receiving device 6 in FIG. 3, showing a case where one computer is used in each of the mail server device 4 and the mail transmitting/receiving device 6.

FIG. 5 is a flow chart which shows one example of processing procedures in the mail server device 4 which configures the mail communication system 2.

FIG. 6 is a flow chart which shows one example of detailed processing procedures in new connection generation processing shown in FIG. 5.

FIG. 7 is a flow chart which shows one example of detailed processing procedures in expiration date extension processing shown in FIG. 5.

FIG. 8 is a flow chart which shows one example of detailed processing procedures in header decode processing shown in FIG. 5.

FIG. 9 is a flow chart which shows one example of detailed processing procedures in header encode processing shown in FIG. 5.

FIG. 10 is a flow chart which shows one example of server-side connection issuance/target addressed transfer mail generation processing procedures in the mail server device 4.

FIG. 11A is a drawing which shows one example of a data arrangement of an account master table 26. FIG. 11B is a drawing which shows one example of a data arrangement of a connection table 27.

FIG. 12 is a drawing which describes processing content in the new connection generation processing shown in FIG. 6.

FIG. 13 is a drawing which describes processing content in the header decode processing shown in FIG. 8.

FIG. 14 is a drawing which describes processing content in the header encode processing shown in FIG. 9.

FIG. 15 is a drawing which describes processing content of the header decode processing in FIG. 8 on retransmission (reply from a registered user to a target).

FIG. 16 is a drawing which shows one example of a data arrangement of a local connection table 37.

FIG. 17 is a flow chart which shows one example of processing procedures in the mail transmitting/receiving device 6 of a registered user which configures the mail communication system 2.

FIG. 18 is a drawing which shows a connection list etc., display screen 80 which is displayed on a display device 64 of the mail transmitting/receiving device 6.

FIG. 19 is a flow chart which shows one example of procedures for transmitting/receiving device-side connection issuance/target addressed mail generation processing.

FIG. 20 is a block diagram which illustrates an arrangement of a mail transmitting/receiving device 106 configured with two or more computers.

FIG. 21 is a drawing which describes processing content of new connection generation processing in another embodiment of the present invention.

FIG. 22 is a drawing which describes processing content of header decode processing in another embodiment of the present invention.

FIG. 23 is a drawing which describes processing content of header encode processing in another embodiment of the present invention.

FIG. 24 is a flow chart which shows one example of References retention processing which configures reply original mail identification history header adjustment processing.

FIG. 25 is a flow chart which shows one example of References restoration processing which configures reply original mail identification history header adjustment processing.

FIG. 26 is a drawing which shows one example of a data arrangement of a References table 28 used in reply original mail identification history header adjustment processing.

FIG. 27 is a drawing which describes transition of message data in the reply original mail identification history header adjustment processing which is executed in the header encode processing.

FIG. 28 is a drawing which describes transition of message data in the reply original mail identification history header adjustment processing which is executed in the header decode processing.

FIG. 29 is a drawing which describes a situation on the assumption that reply of a message is iterated between the mail transmitting/receiving device 6 of a target and the mail transmitting/receiving device 6 of a registered user without execution of any special processing.

FIG. 30 is a drawing which describes a situation that during execution of the reply original mail identification history header adjustment processing, reply of a message is iterated between the mail transmitting/receiving device 6 of the target and the mail transmitting/receiving device 6 of the registered user.

FIG. 31A is a drawing which shows one example of a thread normally displayed on the mail transmitting/receiving device 6 of the registered user. FIG. 31B is a drawing which shows one example of a thread normally displayed on the mail transmitting/receiving device 6 of the target.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a block diagram which shows an arrangement of the electronic mail communication system according to one embodiment of the present invention.

The electronic mail communication system 2 is provided with the mail server device 4 and the plurality of mail transmitting/receiving devices 6, 6, . . . . The mail server device 4 is able to communicate with each of the mail transmitting/receiving devices 6 via the information communication means 8. Each of the mail transmitting/receiving devices 6 has functions to transmit and receive electronic mail.

In addition, in this embodiment, there are assumed a case where the registered user and the target use a mail transmitting/receiving device similar in configuration and a case where they use a mail transmitting/receiving device different in configuration. It is also assumed that the registered user and the target use a mail transmitting/receiving device different in configuration from time to time. Therefore, for convenience, their mail transmitting/receiving devices are not distinguished but they are all expressed as the mail transmitting/receiving device 6. Whenever necessary, they are expressed as the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target.

FIG. 2 is a block diagram which illustrates an arrangement of the mail server device 4.

As shown in FIG. 2, the mail server device 4 is provided with a database 25 and a transfer processing portion 10.

The database 25 stores a target actual address which is an electronic mail address of a target to which electronic mail is transmitted and a user actual address which is an electronic mail address of a registered user of this system 2 for receiving the electronic mail replied by the target in association with a connection identification indicator (hereinafter referred to as “connection ID”) corresponding to a connection address which is a temporary electronic mail address of the registered user and an electronic mail address under control of the mail server device 4.

Further, the database 25 stores a connection ID expiration date which is set for each connection ID and also stores information on whether or not the expiration date of connection ID which is set for each connection ID is to be automatically updated.

In the above described example, the database 25 is provided with an account master table 26 and a connection table 27.

The transfer processing portion 10 is arranged so as to execute transfer processing of electronic mail based on data stored in the database 25 and provided with mail receiving means 11, mail determination means 12, validity determination means 13, encode means 14, mail transmitting means 15, expiration date update means 16, decode means 17, error mail transmitting means 18, connection generation means 19 and connection generation/decode means 20.

The mail receiving means 11 receives electronic mail from the mail transmitting/receiving device 6 via the information communication means 8.

The mail determination means 12 determines whether or not electronic mail received by the mail receiving means 11 is target addressed mail which is to be transmitted to a target from a registered user or user addressed mail which is to be transmitted from the target to the registered user based on header information of the electronic mail.

In this case, the header information of the electronic mail covers a header name which configures a header of electronic mail (that is, a field name) and/or a field value.

There are no particular restrictions for how the determination is made based on which header information. Such an arrangement may be made that determination is, for example, made based on the presence or absence of a dedicated header for determining whether the mail is target addressed mail or user addressed mail or based on a field value of the dedicated header.

In this embodiment, a dedicated header with a field value of a target actual address (for example, an “x-unidto:” header shown in FIG. 13) is newly set as the dedicated header to judge based on the presence or absence of the dedicated header.

That is, judgment is made for whether or not the received electronic mail has the “x-unidto:” header. Where the mail has the header, the mail is judged to be target addressed mail and where the mail does not have the header, the mail is judged not to be target addressed mail. In particular, where, as will be described later, an arrangement is made in such a manner that judgment on whether or not the received electronic mail is connection issuance requesting mail made in advance, that is, in a situation that the received electronic mail is either the target addressed mail or the user addressed mail, it is possible to determine whether the mail is the target addressed mail or the user addressed mail only with reference to the presence or absence of the “x-unidto:” header.

In addition, for example, such an arrangement is possible that judgment is made based on header information of a general header (commonly used header) such as a source header and a destination header.

Where judgment is made, for example, based on a field value of the source header of received electronic mail (for example, a “from:” header shown in FIG. 13), that is, an electronic mail address which is the source of the electronic mail, and if the field value conforms to a user actual address stored in the database 25, determination is made that the electronic mail is the target addressed mail and if the field value conforms to a target actual address, it is the user addressed mail.

However, where judgment is made based on the field value of the source header, and if the source is an electronic mail address other than a user actual address and a target actual address stored in the database 25, it is impossible to determine whether it is the target addressed mail or the user addressed mail.

Therefore, for example, where a target who has received electronic mail from a registered user by using the present system 2 replies from a different electronic mail address, the mail is in principle not determined to be the user addressed mail. This holds true for a case of the target addressed mail.

Where an arrangement is made so as to be determined based on the above described “x-unidto:” header, no such problem will be posed. Therefore, this is favorable.

In this embodiment, the mail receiving means 11 is arranged so as to also receive connection issuance requesting mail from a registered user, that is, electronic mail which identifies a target actual address to request the mail server device 4 for issuing a connection ID. And, the mail determination means 12 is arranged in such a manner that whether or not the electronic mail received by the mail receiving means 11 is the connection issuance requesting mail is determined also based on the header information of the electronic mail.

There are no special restrictions for how the determination is made based on which header information. In this embodiment, such an arrangement is made that judgment is made based on a field value of a destination header of received electronic mail (for example, the “to:” header shown in FIG. 12), that is, an electronic mail address which is a destination of the electronic mail concerned.

For example, judgment is made for whether or not a local part of an electronic mail address which configures the field value corresponds to a user identification indicator stored in the database 25 (a unique identification indicator given for each registered user to identify the registered user). If the local part corresponds thereto, the mail is judged to be a connection issuance requesting mail from the registered user.

In addition, in this embodiment, an arrangement is made in such a manner that the received electronic mail does not have the above described “x-unidto:” header and the local part of the electronic mail address indicated by the destination header does not correspond to a user identification indicator stored in the database 25, the mail is determined to be the user addressed mail.

Next, where the mail determination means 12 has determined that the electronic mail is target addressed mail, the decode means 17 writes a target actual address as a field value of the destination header indicating the destination without changing a text or a subject of the target addressed mail, thereby generating target addressed transfer mail which is electronic mail having a written connection address corresponding to a connection ID as a field value of the source header indicating the source.

In addition, in this example, an arrangement is made in such a manner that without changing the text or the subject of the target addressed mail, a text and a subject of the target addressed transfer mail are provided. The present invention shall not be, however, limited thereto.

For example, it is possible to add a comment and a symbol to the text and the subject of the target addressed mail, thereby giving the text and the subject of the target addressed transfer mail. That is, an arrangement can be made in such a manner that the text of the target addressed transfer mail includes the text of the target addressed mail in its entirety or the subject of the target addressed transfer mail includes the subject of the target addressed mail in its entirety.

Further, where the text or the subject of the target addressed mail does not meet requirements of the present system, for example, excess of a certain length etc., it is possible to partially delete or change the text or the subject of the target addressed mail, thereby giving the text or subject of the target addressed transfer mail. That is, an arrangement can be made in such a manner that the text of the target addressed transfer mail substantially includes the text of the target addressed mail or the subject of the target addressed transfer mail substantially includes the subject of the target addressed mail.

In brief, it is acceptable that an arrangement is made in such a manner that the text and the subject of the target addressed transfer mail are generated without substantially changing the text and the subject of the target addressed mail.

In this embodiment, the decode means 17 is arranged in such a manner that on generation of the target addressed transfer mail, the “x-unidto:” header described in the target addressed mail is deleted.

Where the mail determination means 12 has determined that the electronic mail is the user addressed mail, the encode means 14 generates user addressed transfer mail which is electronic mail having a written user actual address as a field value of the destination header without changing the text and the subject of the user addressed mail. The header information of the user addressed transfer mail is arranged in such a manner that in the mail transmitting/receiving device 6 which has received the user addressed transfer mail, the text of the user addressed transfer mail is rewritten and replied, thereby giving target addressed mail (in this case, retransmission mail addressed to a target).

In order that when mail is replied by the mail transmitting/receiving device 6 which has received the user addressed transfer mail, the mail is given as a target addressed mail, an arrangement may be made in such a manner that the user actual address is written as a field value of the destination header of the user addressed transfer mail and, for example, the target actual address is written as a field value of the source header.

However, in this case, in order that the target addressed mail retransmitted to a target as a reply to the user addressed transfer mail is processed by the decode means 17, the mail is required to pass through the mail server device 4. For this reason, for example, as the user actual address, there are required restrictions such as use of an electronic mail address under control of the mail server device 4.

In this embodiment, the encode means 14 is arranged in such a manner that a connection address is written as a field value of the source header of the user addressed transfer mail. Therefore, the above restrictions are not required.

In this example, an arrangement is made in such a manner that without changing the text and the subject of the user addressed mail, there are provided the text and the subject of the user addressed transfer mail. The present invention shall not be, however, limited thereto.

For example, a comment and a symbol can be added to the text or the subject of the user addressed mail, thereby providing the text and the subject of the user addressed transfer mail. That is, an arrangement can be made in such a manner that the text of the user addressed transfer mail includes the text of the user addressed mail in its entirety or the subject of the user addressed transfer mail includes the subject of the user addressed mail in its entirety.

Further, where the text or the subject of the user addressed mail will not meet requirements of the present system, for example, excess of a certain length etc., it is possible to partially delete or change the text or the subject of the user addressed mail, thereby providing the text or the subject of the user addressed transfer mail. That is, an arrangement can be made in such a manner that the text of the user addressed transfer mail substantially includes the text of the user addressed mail or the subject of the user addressed transfer mail substantially includes the subject of the user addressed mail.

In brief, it is acceptable that an arrangement is made in such a manner that the text and the subject of the user addressed transfer mail are generated without substantially changing the text or the subject of the user addressed mail.

In this embodiment, the encode means 14 adds the “x-unidto:” header as a dedicated header on generation of the user addressed transfer mail. As a target actual address which configures a field value of the thus added “x-unidto:” header, a field value of the source header of the user addressed mail (that is, an electronic mail address which indicates the source of the user addressed mail) is written. The electronic mail address which indicates the source of the user addressed mail is in particular referred to as a reply source actual address.

Therefore, the reply source actual address which is a target actual address is to be described in the thus generated user addressed transfer mail as a field value of the dedicated header.

Where the mail determination means 12 determines that the electronic mail is target addressed mail, the expiration date update means 16 determines whether or not an expiration date of connection ID corresponding to the target addressed mail is automatically updated based on data stored in the database 25. Where the expiration date update means 16 determines to update the expiration date, the expiration date update means 16 updates the expiration date of connection ID stored in the database 25. On the other hand, where the expiration date update means 16 determines not to update the expiration date, it will not update the expiration date of connection ID stored in the database 25.

Where the mail determination means 12 determines that the electronic mail is user addressed mail, the validity determination means 13 determines, prior to processing by the above described encode means 14, whether or not the expiration date of connection ID corresponding to the user addressed mail has expired based on data stored in the database 25. Where the validity determination means 13 determines that the expiration date of connection ID has not expired, control of the user addressed mail is shifted to the encode means 14.

Where the validity determination means 13 determines that the expiration date of connection ID has expired, the error mail transmitting means 18 transmits to the source of the user addressed mail electronic mail to the effect that the user addressed mail has been erroneously transmitted.

Where the mail determination means 12 determines that the electronic mail is connection issuance requesting mail, the connection generation means 19 issues a new connection ID.

Next, the target actual address identified by the connection issuance requesting mail and the user actual address identified by the connection issuance requesting mail or data stored in advance in the database 25 are associated with new connection ID and they are stored in the database 25.

Further, there is generated template mail which is electronic mail having a written user actual address as a field value of a destination header. The template mail is arranged in such a manner that a text of the template mail is rewritten in the mail transmitting/receiving device 6 which has received the template mail and replied, thereby generating target addressed mail.

In this embodiment, the connection generation means 19 is arranged in such a manner that a connection address is written as a field value of a source header of the template mail.

In this embodiment, the connection generation means 19 further adds, as a dedicated header, an “x-unidto:” header in which the target actual address identified by connection issuance requesting mail is given as a field value on generation of the template mail. The target actual address identified by a registered user and stored in the database 25 is in particular referred to as a destination actual address.

Therefore, the destination actual address which is a target actual address is described as a field value of a dedicated header in the thus generated template mail.

Upon receiving of a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted via the information communication means 8 from the mail transmitting/receiving device 6 of a registered user, the connection generation/decode means 20 issues new connection ID.

Next, the target actual address identified by the connection issuance/target addressed transfer mail generation requesting signal and the user actual address identified by the requesting signal or by the data stored in advance in the database 25 are associated with the new connection ID and they are stored in the database 25.

Further, as a field value of the destination header, the target actual address is written and as a field value of a source header, a connection address corresponding to the new connection ID is written. Next, there is generated electronic mail in which the data to-be-transmitted is written as a text.

In addition, the target actual address identified by the connection issuance/target addressed transfer mail generation requesting signal is also a target actual address identified by a registered user and stored in the database 25 and therefore a destination actual address.

The mail transmitting means 15 transmits electronic mail generated in the decode means 17, the encode means 14, the connection generation means 19 or the connection generation/decode means 20 via the information communication means 8 in accordance with header information of the electronic mail.

FIG. 3 is a block diagram which illustrates an arrangement of the mail transmitting/receiving device 6.

As shown in FIG. 3, the mail transmitting/receiving device 6 is provided with a mail processing portion 30 and a local database 35. The local database 35 is made up of data which is the same as a part of data stored in the database 25 of the mail server device 4. Use of the local database 35 makes it possible that a part of processing at the mail processing portion 30 of the mail transmitting/receiving device 6 etc., will be executed without communication with the mail server device 4.

In this example, the local database 35 is provided with a local connection table 37.

No local database 35 is needed in the mail transmitting/receiving device 6 of a target. And, in the mail transmitting/receiving device 6 of a registered user, the local database 35 is not necessarily required in processing in the mail processing portion 30 etc., and may be provided, whenever necessary.

The mail processing portion 30 is provided with mail client means 31, connection issuance requesting means 32, transmitting/receiving device-side connection issuance/mail generating means 33, target addressed mail generating means 34, and connection list etc., displaying means 39.

No means other than the mail client means 31 is required in the mail processing portion 30 of the mail transmitting/receiving device 6 of a target. In the mail processing portion 30 of the mail transmitting/receiving device 6 of a registered user as well, means other than the mail client means 31 are not necessarily required and may be provided, whenever necessary.

Upon input of a signal which identifies a target actual address to request issuance of connection ID, the connection issuance requesting means 32 generates a connection issuance requesting mail and transmits the mail to the mail server device 4 via the information communication means 8. The signal which identifies the target actual address to request issuance of connection ID is input, for example, from an input device 66 of the mail transmitting/receiving device 6.

The connection issuance requesting mail is electronic mail which identifies a target actual address and requests the mail server device 4 to issue a new connection ID, associates the connection ID with the target actual address and the user actual address and store them in the database 25 and also requests it to generate template mail and transmit the mail to the user actual address.

There are no particular restrictions for an electronic mail address which is a destination of the connection issuance requesting mail. Preferably the electronic mail address is an electronic mail address under control of the mail server device 4 and is able to identify the registered user concerned. In this embodiment, a local part made up of the user identification indicator and a domain name indicating the mail server device 4 are used to configure an electronic mail address which is a destination of the connection issuance requesting mail.

The transmitting/receiving device-side connection issuance/mail generating means 33 is means on the side of the mail transmitting/receiving device 6 which configures connection issuance/mail generating means. The connection issuance/mail generating means is such means that continuously executes, as sequential processing, issuance and registration of new connection ID and generation and transmission of electronic mail (target addressed mail or target addressed transfer mail) by using a connection address corresponding to the connection ID.

In this embodiment, a description will be given of a case where the electronic mail generated in the connection issuance/mail generating means is target addressed transfer mail.

The connection issuance/mail generating means of this case is in particular referred to as connection issuance/target addressed transfer mail generating means, and the means on the side of the mail transmitting/receiving device 6 is referred to as transmitting/receiving device-side connection issuance/target addressed transfer mail generating means. That is, in this embodiment, the transmitting/receiving device-side connection issuance/mail generating means 33 denotes transmitting/receiving device-side connection issuance/target addressed transfer mail generating means.

That is, upon input of a signal which identifies a target actual address and data to-be-transmitted to request generation of a connection issuance/target addressed transfer mail generation requesting signal, the transmitting/receiving device-side connection issuance/mail generating means 33, as the transmitting/receiving device-side connection issuance/target addressed transfer mail generating means, generates a connection issuance/target addressed transfer mail generation requesting signal and transmits the signal via the information communication means 8 to the mail server device 4. The signal which identifies a target actual address and data to-be-transmitted to request generation of the connection issuance/target addressed transfer mail generation requesting signal is input, for example, from the input device 66 of the mail transmitting/receiving device 6.

The connection issuance/target addressed transfer mail generation requesting signal is a signal which identifies the target actual address and data to-be-transmitted, thereby requesting the mail server device 4 to issue a new connection ID, associate the connection ID with the target actual address and the user actual address and store them in the database 25. And, this signal is also a signal which gives the data to-be-transmitted as a text, thereby generating electronic mail similar to target addressed transfer mail generated in the decode means 17, and requesting to transmit the mail to the target actual address.

In this embodiment, the connection issuance/target addressed transfer mail generation requesting signal contains data which identifies a user actual address designated by a registered user.

Upon input of the signal which identifies the connection ID and the data to-be-transmitted to request generation of target addressed mail, the target addressed mail generating means 34 generates target addressed mail to a target associated with the connection ID in which the data to-be-transmitted is given as a text, and transmits the mail via the information communication means 8 to the mail server device 4. The signal which requests generation of the target addressed mail is input, for example, from the input device 66 of the mail transmitting/receiving device 6.

The mail client means 31 is configured with, for example, a general (that is, for general use) mail client program (or MUA, that is, mail user agent) and is able to execute generation, transmission, receiving, browsing, edit, reply etc., of electronic mail.

It is acceptable that transmission/receiving processing of electronic mail in the above described various types of means of the mail transmitting/receiving device 6 is executed by utilizing a whole or a part of functions of the mail client means 31 or by utilizing similar functions which are provided separately.

The connection list etc., displaying means 39 displays a connection list etc., display screen 80 on the display device 64 of the mail transmitting/receiving device 6 of a registered user (refer to FIG. 18).

On the connection list etc., display screen 80, there is displayed a connection list 81 which lists and displays connection name buttons 81 a, 81 b, . . . which describe connection names (titles of connection identified by connection ID) indicating the connection ID associated with the registered user.

On the connection list etc., display screen 80, there are also displayed a new connection button 82 and a new connection/mail generating button 83.

The connection list etc., display screen 80 also functions as the input device 66 of the mail transmitting/receiving device 6. Where the new connection button 82 is selected (for example, click and tap, the same shall be applied hereinafter), processing is started by the connection issuance requesting means 32.

Where the new connection/mail generating button 83 is selected, processing is started by the transmitting/receiving device-side connection issuance/mail generating means 33.

Where any one of the connection name buttons 81 a, 81 b, . . . is selected, processing is started by the target addressed mail generating means 34 related to the connection ID corresponding to the thus selected connection name button.

FIG. 4 is a block diagram which shows one example of the mail server device 4 shown in FIG. 2 and a hardware arrangement of the mail transmitting/receiving device 6 shown in FIG. 3. This diagram shows an example where as the mail server device 4 and the mail transmitting/receiving device 6, one computer is used in each of them.

Although there are no particular restrictions, in this example, the mail server device 4 is arranged in a similar manner to a generally used server computer.

The mail server device 4 is provided with an auxiliary storage device 50 such as a HDD (hard disk drive) having a hard disk which is a record medium storing programs on the side of the mail server device 4 of the electronic mail communication system 2, and which is also a storage medium of the database 25, a main storage device 48 into which a program stored in the auxiliary storage device 50 is loaded, a CPU 42 corresponding to the transfer processing portion 10 which executes the program loaded into the main storage device 48, a display device 44 such as a LCD (liquid crystal display device), an input device 46 such as a keyboard, a mouse or a track pad, and a communication interface 52 which communicates with the mail transmitting/receiving device 6 via the information communication means 8.

There are no particular restrictions for the mail transmitting/receiving device 6. The transmitting/receiving device 6 may include a personal computer, a tablet-type computer, a personal digital assistant device and a portable cellular phone, a typical example of which is a so-called smart phone.

The mail transmitting/receiving device 6 is provided with an auxiliary storage device 70 such as a SSD (solid state drive) equipped with a flash memory which is a record medium storing programs on the side of the mail transmitting/receiving device 6 of the electronic mail communication system 2, a main storage device 68 into which a program stored in the auxiliary storage device 70 is loaded, a CPU 62 corresponding to the mail processing portion 30 which executes the program loaded into the main storage device 68, a display device 64 such as a LCD (liquid crystal display device), an input device 66 such as an input key and a touch panel, and a communication interface 72 which communicates with the mail server device 4 via the information communication means 8.

The information communication means 8 is communication means for delivering information converted to an electrical signal, a light signal etc., irrespective of whether it is based on wire or radio communication. The information communication means 8 includes, for example, a computer network such as WAN (wide area network) represented by the Internet or LAN (local area network), a telephone line (including a portable cellular phone line), a communication line such as a dedicated line, a direct connection by communication cables and infrared light etc., or a combination of them.

Each of FIG. 5 to FIG. 10 is a flow chart which shows one example of processing procedures of the mail server device 4 which configures the electronic mail communication system 2.

FIG. 12 is a drawing which describes processing content of the new connection generation processing shown in FIG. 6. FIG. 13 is a drawing which describes processing content of the header decode processing in FIG. 8. FIG. 14 is a drawing which describes processing content of the header encode processing shown in FIG. 9. FIG. 15 is a drawing which describes content of the header decode processing in FIG. 8 on retransmission (reply of a registered user to a target).

FIG. 11A is a drawing which shows one example of data arrangement in an account master table 26. FIG. 11B is a drawing which shows one example of data arrangement in a connection table 27.

As shown in FIG. 11A, the account master table 26 stores account information related to attributes of the registered user who is a registered user of the present system 2. Each of the records stored in the account master table 26 is referred to as an account record.

Of fields of the account master table 26, an unID account 26 a denotes a user identification indicator.

In addition, in the present description, unless otherwise specified, that denoted by a field name of the database 25 (that is, the account master table 26 and the connection table 27) with a reference number, (for example, an “unID account 26 a”) is to indicate data of the field concerned.

A default actual address 26 d denotes an electronic mail address of default of the registered user.

Reply destination address setting 26 e of the account master table 26 designated by the registered user is data designated for how to identify an electronic mail address which is a destination of user addressed transfer mail (that is, a user actual address) in the header encode processing shown in FIG. 9.

Where “default” is designated by the reply destination address setting 26 e, the default actual address 26 d is assigned as the user actual address. On the other hand, where “source” is designated, a source actual address 27 e which is one field of the connection table 27 shown in FIG. 11B is assigned as the user actual address.

In other words, the default actual address 26 d of the account master table 26 or the source actual address 27 e of the connection table 27 corresponds to the user actual address.

Of fields of the account master table 26, an extension period setting value 26 f indicates an extension period of connection ID.

Next, the connection table 27 shown in FIG. 11B stores connection information related to a relationship between a registered user and a target. Each of records stored in the connection table 27 is referred to as a connection record.

Of fields of the connection table 27, the connection ID 27 b is data indicating connection ID. The connection ID corresponds to a connection address which is a temporary electronic mail address of the registered user and, inmost cases, unique data automatically given by the mail server device 4. In other words, the connection ID is an identification indicator which indicates a connection between a user and a target via electronic mail being set for each purpose.

In this example, the connection address is configured with a local part made up of the connection ID and a domain name indicating the mail server device 4.

Where the connection ID and the connection address are correlated uniquely (that is, in a one-to-one relationship), the connection address is not necessarily limited to that which is configured with a local part made up of the connection ID and a domain name indicating the mail server device 4. As a matter of course, the connection ID and the connection address may be the same.

An unID account 27 c of the connection table 27 is the same data as the unID account 26 a of the account master table 26. The unID account 27 c and the unID account 26 a are used to associate a connection record of the connection table 27 with an account record of the account master table 26.

The destination actual address 27 d is a target actual address usually given by a registered user on issuance of new connection ID. The destination actual address 27 d, or a reply source actual address which is an electronic mail address configuring a field value of the source header of the above described user addressed mail corresponds to a target actual address.

Next, the source actual address 27 e is usually an electronic mail address of a source of the above described connection issuance requesting mail acquired by the mail server device 4 or a user actual address which is identified by the connection issuance/target addressed transfer mail generation requesting signal.

In this example, the mail server device 4 is arranged in such a manner as to additionally acquire an electronic mail address of a source of the received target addressed mail every time target addressed mail is received from a registered user and to update the source actual address 27 e by the thus acquired electronic mail address. Therefore, in this example, the source actual address 27 e is given as an electronic mail address of a source of the immediate (newest) target addressed mail.

An expiration date 27 g is an expiration date of connection ID (that is, an expiration date of the connection address).

An automatic update 27 i is data which shows whether or not the expiration date is automatically updated in the expiration date extension processing shown in FIG. 7. Where the data is “1,” automatic update is executed, and where it is “0,” no automatic update is executed.

Nullification 27 k is data which shows whether or not the connection ID is invalid. Where the data is “1,” the connection ID is invalid. Where the data is “0,” the connection ID is valid. Where the connection ID has expired or where a registered user cancels before an expiration date of the connection ID even within the expiration date, the nullification is “1” and thereafter, user addressed mail from a target will no longer be transferred to the registered user.

It is acceptable that judgment on whether the connection ID is valid or invalid based on the nullification 27 k is made at the same time, for example, with judgment of the expiration date by the validity determination means 13 shown in FIG. 2 (processing shown in Step S9 and Step S10 corresponding thereto and to be described later).

Of fields of the connection table 27, about a field configured with the same quality data as a field of the account master table 26 except the unID account 27 c, that is, in this example, about reply destination address setting 27 f and extension period setting value 27 h of the connection table 27 (in this example, the field name is also the same as that of the account master table 26), data of the connection table 27 is used preferentially.

Therefore, where significant data is described in these fields of the connection table 27, the data is used in corresponding processing. Where no significant data is described in the connection table 27 (for example, when the data concerned is “null”), data of the corresponding account master table 26 is used.

Next, a description will be given of processing procedures in the mail server device 4 with reference to FIG. 5 to FIG. 15.

In addition, in drawings of the present application, a character string described in < > denote an item name of data, those indicated with <item name> indicate data of an item denoted by the item name, unless otherwise specified. Where the item name is a field name of the database 25 (that is, the account master table 26 and the connection table 27), unless otherwise specified, <fieldname> (for example, <connection ID>) indicates data of the corresponding field of the database 25. Further, a character string described in “ ” are to indicate data in itself.

As shown in FIG. 5, the CPU 42 of the mail server device 4 (refer to FIG. 4) monitors incoming of electronic mail. Upon receiving of electronic mail (Step S1), the CPU 42 judges whether or not the electronic mail has an “x-unidto:” header which is a dedicated header (Step S2).

In Step S2, where the CPU 42 judges that it has no “x-unidto:” header, a local part of a “to:” header which is a destination header of the electronic mail is verified with the unID account 26 a of the account master table 26 (Step S3). If they are matched, the CPU 42 determines that the electronic mail is a connection issuance requesting mail from a registered user corresponding to the matched unID account 26 a (Step S4) and executes new connection generation processing (Step S5).

FIG. 12 illustrates an arrangement of connection issuance requesting mail 91 transmitted from the mail transmitting/receiving device 6 of the registered user.

As shown in FIG. 6, in the new connection generation processing, the CPU 42 issues a new connection ID (Step S21) and registers a new connection record corresponding to the new connection ID in the connection table 27 (Step S22).

That is, new connection records made up of predetermined fields such as the new connection ID 27 b, the unID account 27 c of the registered user, the destination actual address 27 d identified in a text of the connection issuance requesting mail 91, the source actual address 27 e which is a field value of a source header of the connection issuance requesting mail 91 are added to the connection table 27.

In this example, as a specific arrangement which identifies the destination actual address 27 d added to the connection table 27 in the new connection generation processing by the connection issuance requesting mail 91, there is illustrated a method for describing the destination actual address 27 d in the text of the connection issuance requesting mail 91. The specific arrangement which identifies the destination actual address 27 d by the connection issuance requesting mail 91 shall not be limited thereto.

There is, for example, a method in which the destination actual address 27 d is described in a header of the connection issuance requesting mail 91. To be more specific, there can be illustrated a method in which a general header such as a subject header indicating a subject is used or a dedicated header is provided, thereby describing the destination actual address 27 d as a field value of the header concerned.

Further, in the example, as the source actual address 27 e added to the connection table 27 in the new connection generation processing, there is used a field value of a source header of the connection issuance requesting mail 91. The source actual address 27 e added to the connection table 27 in the new connection generation processing shall not be limited thereto.

As the source actual address 27 e added to the connection table 27 in the new connection generation processing, for example, an arrangement can be made in such a manner that there is used an electronic mail address which is designated arbitrarily by a registered user in the text or the header of the connection issuance requesting mail 91 (use of a general header or setting of a new dedicated header), an arrangement is made in such a manner that as the source actual address 27 e, there is used an electronic mail address of a registered user which has been in advance stored in the database 25 (for example, the default actual address 26 d of the account master table 26), or an arrangement is made so that the registered user is allowed to select one of the above described methods.

Moreover, where there is used a field value of a source header of the connection issuance requesting mail 91 as the source actual address 27 e added to the connection table 27 in the new connection generation processing, an arrangement is made in such a manner that a desired electronic mail address can be selected from electronic mail addresses those are retained by the registered user (that is, mail accounts) and the connection issuance requesting mail 91 can be transmitted from the selected electronic mail address. Thereby, the registered user is able to receive template mail at a desired electronic mail address.

Regarding data of a field other than the fields described above, of fields of the connection record shown in FIG. 11B, an arrangement can be made in such a manner that data determined in advance is generated in the mail server device 4, the data is identified in the connection issuance requesting mail, the data is directly transmitted to the mail server device 4 in the connection issuance requesting means 32 of the mail transmitting/receiving device 6 shown in FIG. 3, or these methods are combined.

Next, the CPU 42 generates template mail (Step S23) and transmits the mail (FIG. 5, Step S6).

FIG. 12 illustrates an arrangement of the template mail 92 which has been transmitted from the mail server device 4.

The template mail 92 which has been transmitted from the mail server device 4 is transmitted to a source actual address of the mail transmitting/receiving device 6 of a registered user. The registered user who has received the mail rewrites the text thereof and replies with the mail, which is target addressed mail.

FIG. 13 illustrates an arrangement of the target addressed mail 93 replied from the mail transmitting/receiving device 6 of the registered user.

The target addressed mail 93 replied from the mail transmitting/receiving device 6 of the registered user is transmitted to a corresponding connection address of the registered user set in the mail server device 4.

By reverting to FIG. 5, where the thus received electronic mail is judged to have the “x-unidto:” header in Step S2, the CPU 42 determines that the received electronic mail is the target addressed mail 93 and executes expiration date extension processing (Step S7).

In the expiration date extension processing shown in FIG. 7, the CPU 42 acquires necessary data such as automatic update 27 i from a connection record corresponding to the connection ID which configures a local part of the “to:” header of the target addressed mail 93 in the connection table 27 (Step S31) and judges whether the acquired automatic update 27 i is “1” or “0” (Step S32).

Where the CPU 42 judges that the automatic update 27 i is “1,” it determines that the expiration date 27 g is updated. Further, the CPU 42 checks whether or not the data is described in an extension period setting value 27 h of the connection table 27 (Step S33).

Where the CPU 42 judges that the data is described in the extension period setting value 27 h of the connection table 27, the CPU 42 updates the expiration date 27 g of the connection table 27 to that in which the extension period setting value 27 h is added to the present time (that is, data which indicates the present date retained in the mail server device 4) (Step S35).

On the other hand, where the CPU 42 judges that nothing is described in the extension period setting value 27 h of the connection table 27 in Step S33, it acquires the extension period setting value 26 f described in the account master table 26 (Step S34) and executes processing of above described Step S35 based on the acquired extension period setting value 26 f.

By reverting to FIG. 5, the CPU 42 then executes header decode processing (Step S8).

As shown in FIG. 8, the CPU 42 executes basic header decode processing (Step S41). In the basic header decode processing, first, a “from:” header of the received target addressed mail 93 (refer to FIG. 13) is deleted. The header name of “to:” header is changed to “from:” and the header name of “x-unidto:” header is changed to “to:.”

Next, the CPU 42 checks a field value of a “cc:” header (Step S42). Where the field value is other than “replyAll,” or where the “cc:” header itself is not found, the CPU 42 terminates header decode processing. And where the field value is “replyAll,” the CPU 42 executes additional header decode processing (Step S43) and then terminates the header decode processing. The additional header decode processing will be described later.

The CPU 42 transmits target addressed transfer mail acquired by giving the header decode processing to the received target addressed mail 93 (FIG. 5, Step S6).

FIG. 13 illustrates an arrangement of target addressed transfer mail 94.

The target addressed transfer mail 94 transmitted from the mail server device 4 is transmitted to a destination actual address of the mail transmitting/receiving device 6 of a target. The target who has received the mail rewrites a text thereof and replies with the mail, which is user addressed mail.

FIG. 14 illustrates an arrangement of the user addressed mail 95 replied from the mail transmitting/receiving device 6 of the target.

A field value of the “from:” header of the user addressed mail 95 is <reply source actual address> which indicates an electronic mail address of a source of the user addressed mail 95. Where a target who has received the target addressed transfer mail 94 (refer to FIG. 13) replies from the thus received electronic mail address, data which configures the <reply source actual address> is equal to data of the destination actual address 27 d stored in the connection table 27.

The user addressed mail 95 replied from the mail transmitting/receiving device 6 of the target is transmitted to a corresponding connection address of the registered user set in the mail server device 4. That is, a destination of the user addressed mail 95 is the same as a destination of the above described target addressed mail 93.

In addition, where the user addressed mail 95 is involved in broadcast transmission, there is added a “cc:” header in which a broadcast destination actual address designated by the target is added as a field value.

By reverting to FIG. 5, where the CPU 42 judges that the received electronic mail does not have the “x-unidto:” header in Step S2 and also that a local part of the “to:” header of the electronic mail is not matched with the unID account 26 a of the account master table 26 in Step S4, the CPU 42 determines that the received electronic mail is the user addressed mail 95 and acquires the expiration date 27 g which is a field of a corresponding connection record of the destination connection address from the connection table 27 (Step S9).

Next, the CPU 42 judges whether or not the present time is out of the expiration date 27 g (Step S10). Where the CPU 42 judges expiration of the date, it determines that the connection ID is out of date and generates error mail to the effect of such expiration and transmits a reply message to a target (Step S11).

On the other hand, where the CPU 42 judges that the present time is not out of the expiration date 27 g in Step S10, it judges that the connection ID is not out of date and executes header encode processing (Step S12).

As shown in FIG. 9, in the header encode processing, the CPU 42 first acquires a user actual address which is associated with the connection ID and given as a transfer destination of the received user addressed mail 95 (Step S51).

That is, the CPU 42 checks the reply destination address setting 27 f corresponding to the connection ID 27 b of the connection table 27 and acquires the source actual address 27 e of the connection table 27 where “source” is described in the reply destination address setting 27 f, thereby giving the source actual address 27 e as a user actual address.

On the other hand, where “default” is described in the reply destination address setting 27 f of the connection table 27, the CPU 42 acquires from the account master table 26 a default actual address 26 d of an account record corresponding to the unID account 26 a corresponding to the connection ID 27 b, thereby giving the default actual address 26 d as a user actual address.

Where nothing is described in the reply destination address setting 27 f of the connection table 27, the CPU 42 checks reply destination address setting 26 e of an account record corresponding to the unID account 26 a corresponding to the connection ID 27 b of the account master table 26, executing processing similar to the above described processing in accordance with data of the reply destination address setting 26 e.

When the user actual address is decided as described above, basic header encode processing is executed (Step S52).

In the basic header encode processing, the “to:” header of the thus received user addressed mail 95 (refer to FIG. 14) is deleted and there is added the “to:” header in which a field value is given as a user actual address (that is, the default actual address 26 d or the source actual address 27 e). And the header name of the “from:” header is changed to “x-unidto:” and there is added the “from:” header in which a field value is given as a connection address corresponding to the connection ID.

Next, the CPU 42 checks the presence or absence of the “cc:” header (Step S53). Where no “cc:” header is found, the CPU 42 terminates header encode processing. Where the “cc:” header is found, the CPU 42 executes additional header encode processing and thereafter terminates the header encode processing (Step S54).

In the additional header encode processing, the header name of the “cc:” header of the received user addressed mail 95 is changed to “x-unidcc:” which indicates a dedicated header in which the broadcast destination actual address is given as a field value. There is added a “cc:” header in which the field value is given as “replyAll.”

The CPU 42 transmits user addressed transfer mail acquired by giving the header encode processing to the received user addressed mail 95 (FIG. 5, Step S6).

FIG. 14 illustrates an arrangement of the user addressed transfer mail 96.

The user addressed transfer mail 96 transmitted from the mail server device 4 is transmitted to a user actual address (that is, the default actual address 26 d or the source actual address 27 e) of the mail transmitting/receiving device 6 of a registered user.

Further, a description will be given of a case where a registered user who has received the mail rewrites a text thereof and retransmits the mail (that is, the mail is replied to a target). In the present system 2, electronic mail retransmitted from the registered user is also handled as target addressed mail and subjected to processing similar to the above described target addressed mail 93 (refer to FIG. 13).

FIG. 15 illustrates an arrangement of target addressed mail 97 retransmitted (replied) from the mail transmitting/receiving device 6 of the registered user. In this example, the user actual address of the registered user is regarded as a source actual address 27 e as well. Further, where the user addressed mail 95 (refer to FIG. 14) from the target is involved in broadcast transmission, it is assumed that the registered user will reply to all the broadcast destination actual addresses.

In this case, in Step S42 covering the header decode processing shown in FIG. 8, a field value of the “cc:” header is judged to be “replyAll” and additional header decode processing is executed.

In the additional header decode processing, the “cc:” header of the target addressed mail 97 is deleted and the header name of the “x-unidcc:” header is changed to “cc:.”

FIG. 15 illustrates an arrangement of the thus generated target addressed transfer mail 98.

In the present system 2, as described above, electronic mail retransmitted (replied) from a registered user to a target or even mail replied to the above mail is subjected to processing similar to that of first target addressed mail or first user addressed mail, irrespective of the number of times.

That is, where the mail transmitting/receiving device 6 of the registered user or that of the target is provided only with general mail client means 31 (refer to FIG. 3), it is possible to repeat transmission of electronic mail from the registered user to the target, reply from the target, retransmission (a reply to a previous reply), another reply (reply in response to retransmission) and others.

On the other hand, where new electronic mail (target addressed mail) is generated and transmitted to a target with already registered connection ID, the mail transmitting/receiving device 6 of the registered user may be used to execute, for example, target addressed mail generation processing to be described later (FIG. 17, Step S75).

Next, a description will be given of server-side connection issuance/target addressed transfer mail generation processing with reference to FIG. 10.

The CPU 42 of the mail server device 4 monitors a connection issuance/target addressed transfer mail generation requesting signal. Upon receiving of the connection issuance/target addressed transfer mail generation requesting signal by which a destination actual address as a target actual address and data to-be-transmitted are identified via the information communication means 8 from the mail transmitting/receiving device 6 of the registered user, the CPU 42 issues a new connection ID (Step S61) and also registers a new connection record corresponding to the new connection ID in the connection table 27 (Step S62).

That is, there is added to the connection table 27 the new connection record made up of predetermined fields such as a new connection ID 27 b, an unID account 27 c of the registered user, a destination actual address 27 d identified by the connection issuance/target addressed transfer mail generation requesting signal and a source actual address 27 e etc.

In this example, in the server-side connection issuance/target addressed transfer mail generation processing, as the source actual address 27 e to be added to the connection table 27, there is used an electronic mail address of the mail transmitting/receiving device 6 which is a source of the requesting signal (this can be realized, for example, by allowing an electronic mail address used mainly in the mail transmitting/receiving device 6 which is a source of the requesting signal to be included in the connection issuance/target addressed transfer mail generation requesting signal). However, the source actual address 27 e added to the connection table 27 in the server-side connection issuance/target addressed transfer mail generation processing shall not be limited thereto.

In the server-side connection issuance/target addressed transfer mail generation processing, as the source actual address 27 e to be added to the connection table 27, for example, an arrangement can be made so as to use an electronic mail address arbitrarily designated by a registered user (this can be realized, for example, by allowing the electronic mail address arbitrarily designated by the registered user to be included in the requesting signal), an arrangement can be made so as to use an electronic mail address of the registered user stored in advance in the database 25, as the above described source actual address 27 e, (for example, the default actual address 26 d of the account master table 26), and an arrangement can also be made in such a manner that the registered user is able to select one of these methods.

Similar to the above described new connection generation processing (refer to FIG. 6), regarding data of the fields other than those described above, of the fields of the connection record given in FIG. 11B, it is acceptable that predetermined data is generated in the mail server device 4. It is also acceptable that an arrangement is made in such a manner that these data are identified by the connection issuance/target addressed transfer mail generation requesting signal or above described methods are combined.

Next, the CPU 42 generates electronic mail in which the destination actual address 27 d has been written as a field value of the destination header, a connection address corresponding to the new connection ID 27 b has been written as a field value of the source header, data to-be-transmitted has been written as a text (Step S63), and transmits the mail (Step S64).

In Step S64, the electronic mail which has been transmitted from the mail server device 4 is, unlike a case where it is transmitted via the new connection generation processing (refer to FIG. 6), transmitted to the destination actual address 27 d of the mail transmitting/receiving device 6 of the target by a single operation of the mail transmitting/receiving device 6 of the registered user, that is, transmitting/receiving device-side connection issuance/mail generation processing to be described later (FIG. 17, Step S74).

An arrangement of the electronic mail is the same as that of the target addressed transfer mail 94 shown in FIG. 13. In the present system 2, the mail is processed in the same manner as the target addressed transfer mail 94. Therefore, unless otherwise specified, the above described electronic mail is described as the target addressed transfer mail 94.

Next, FIG. 16 is a drawing which shows one example of data arrangement of a local connection table 37 which configures local database 35 of the mail transmitting/receiving device 6. The data arrangement of the local connection table 37 is the same as the data arrangement of the connection table 27 shown in FIG. 11B except that data corresponding to the unID account 27 c is not included. However, the local connection table 37 stores only the connection record related to the registered user identified by the unID account 27 c of the connection table 27.

The data of the local connection table 37 and the data of the connection table 27 are subjected to synchronization via the information communication means 8, whenever necessary, and the identification is kept.

FIG. 17 is a flow chart which shows one example of processing procedures of the mail transmitting/receiving device 6 of the registered user which configures the mail communication system 2.

FIG. 18 is a drawing for describing processing shown in FIG. 17, and a drawing which indicates a connection list etc., display screen 80 displayed on a display device 64 of the mail transmitting/receiving device 6.

Next, with reference to FIG. 17, a description will be given of processing procedures in the mail transmitting/receiving device 6 of the registered user.

As shown in FIG. 17, a CPU 62 (refer to FIG. 4) of the mail transmitting/receiving device 6 displays the connection list etc., display screen 80 on the display device 64 (Step S71) and monitors input from an input device 66 (Step S72).

Each of connection names (for example “e-mate query”) described in connection name buttons 81 a, 81 b, . . . which configure a connection list 81 displayed on the connection list etc., display screen 80 may be acquired by extracting a connection name 27 j corresponding to connection ID related to the registered user from the connection table 27 of the mail server device 4. However, in this embodiment, all the connection names 37 j stored in the local connection table 37 of the mail transmitting/receiving device 6 are to be acquired.

Here, upon selection of the new connection button 82 of the connection list etc., display screen 80, the CPU 62 judges that a registered user has requested connection issuance, thereby requesting input of a destination actual address of a target. Upon this input, the CPU 62 generates connection issuance requesting mail 91 (refer to FIG. 12) based on the thus input destination actual address and transmits the mail via the information communication means 8 to the mail server device 4 (Step S73).

As described above, in the mail server device 4 which has received the connection issuance requesting mail 91, new connection generation processing is executed (refer to FIG. 6) and template mail 92 (refer to FIG. 12) is transmitted to a source actual address of the registered user.

In Step S72, upon selection of a new connection/mail generating button 83 of the connection list etc., display screen 80, the CPU 62 judges that the registered user has requested generation of connection issuance/target addressed transfer mail, thereby requesting input of a destination actual address of the target, data to-be-transmitted which is a text of electronic mail and data which is a subject of electronic mail. Upon input, the CPU 62 generates the above described connection issuance/target addressed transfer mail generation requesting signal based on the thus input data and transmits the signal via the information communication means 8 to the mail server device 4 (Step S74).

As described above, in the mail server device 4 which has received the connection issuance/target addressed transfer mail generation requesting signal, server-side connection issuance/target addressed transfer mail generation processing is executed (refer to FIG. 10), and target addressed transfer mail 94 is transmitted to the destination actual address of the target.

In Step S72, upon selection of any one of connection name buttons 81 a, 81 b, . . . which configure the connection list 81 of the connection list etc., display screen 80, target addressed mail generation processing is executed (Step S75).

A description will be given of a reason why the target addressed mail generation processing is required.

As described above, where electronic mail in which a field value of the “from:” header of a source header is a connection address and the “x-unidto:” header of a dedicated header is described, for example, template mail 92 (refer to FIG. 12), and user addressed transfer mail 96 (refer to FIG. 14) is retained in the mail transmitting/receiving device 6 of the registered user, the electronic mail is replied, by which it is possible to generate and transmit at any number of times the target addressed mail 93 shown in FIG. 13 (in the case of retransmission shown in FIG. 15, target addressed mail 97 is included).

However, in a case where the template mail 92 or the user addressed transfer mail 96 is not retained in the mail transmitting/receiving device 6 of the registered user, for example, a case where the electronic mail has been already deleted from the mail transmitting/receiving device 6 or a case where the electronic mail is desired to be transmitted from a mail transmitting/receiving device 6 different from the mail transmitting/receiving device which retains the electronic mail, it is impossible to generate and transmit the target addressed mail 93 by a method for replying to these electronic mail.

The target addressed mail generation processing (Step S75) is a processing which enables generation and transmission of the target addressed mail 93 by using an existing connection address in the mail transmitting/receiving device 6, even in the above described cases.

Now, in the target addressed mail generation processing, the CPU 62 judges that the registered user has requested generation of the target addressed mail, thereby requesting input of data to-be-transmitted which is a text of electronic mail and data which is a subject of the electronic mail.

Upon input, the CPU 62 generates the target addressed mail described in the “x-unidto:” header of a dedicated header based on these thus input data, a connection ID corresponding to the selected connection name button and a destination actual address corresponding to the connection ID and transmits the mail via the information communication means 8 to the mail server device 4 (Step S75).

The destination actual address corresponding to the connection ID may be such that the destination actual address 27 d corresponding to the connection ID is acquired from the connection table 27 of the mail server device 4. However, in this embodiment, acquired is a destination actual address 37 d stored at the local connection table 37 of the mail transmitting/receiving device 6.

As described so far, the target addressed mail which has been transmitted to the mail server device 4 is arranged in the similar way as that of the target addressed mail 93 in which the text and the subject of the template mail 92 (refer to FIG. 12) are rewritten and replied (refer to FIG. 13). In the mail communication system 2, the mail is processed in the similar way as the target addressed mail 93. Therefore, the target addressed mail which has been generated and transmitted in Step S75 is also described as the target addressed mail 93.

As described above, thereafter, in the mail server device 4 which has received the target addressed mail 93, expiration date extension processing (refer to FIG. 7) and header decode processing (refer to FIG. 8) are executed, and the target addressed transfer mail 94 (refer to FIG. 13) is transmitted to the destination actual address of the target.

The target addressed mail generation processing in Step S75 shall not be limited to the above described method.

For example, the template mail 92 generated by the new connection generation processing (refer to FIG. 5, Step S5) and received by the mail transmitting/receiving device 6 (refer to FIG. 12) is arranged so as to be stored and retained in a storage device of the mail transmitting/receiving device 6 (for example, a main storage device 68 or an auxiliary storage device 70 shown in FIG. 4). It is preferable that the template mail 92 is in principle kept non-erasable.

Then, upon selection of any one of the connection name buttons 81 a, 81 b, . . . which configure the connection list 81 of the connection list etc., display screen 80, the CPU 62 judges that the registered user has requested generation of target addressed mail, thereby requesting input of data to-be-transmitted which is a text of electronic mail and data which is a subject of the electronic mail.

Upon input, the CPU 62 reads out template mail 92 corresponding to a connection ID corresponding to the selected connection name button from the template mail stored in the storage device, rewrites the text of the template mail 92 into the data to-be-transmitted, writes the input data as the subject, generates target addressed mail and replies with the mail via the information communication means 8 to the mail server device 4.

According to the above arrangement, on execution of the target addressed mail generation processing shown in Step S75, there is eliminated a necessity for processing in which the “x-unidto:” header or a dedicated header is newly added in the mail transmitting/receiving device 6. As a result, it is not necessary to give dedicated electronic mail generating functions to the mail transmitting/receiving device 6. There may be used, for example, functions of the mail client means 31 shown in FIG. 3.

As a matter of course, electronic mail which is in principle kept non-erasable may not be necessarily the template mail 92. For example, it may be the (newest) user addressed transfer mail 96. In brief, it is acceptable that the electronic mail which is in principle kept non-erasable is such electronic mail that a field value of the “from:” header of a source header is a connection address and the “x-unidto:” header of a dedicated header is described.

However, the target addressed mail generation processing described at the beginning is advantageous in that the processing can be executed even where the template mail 92 or the user addressed transfer mail 96 is not retained in the mail transmitting/receiving device 6.

Now in the above described embodiment, a description has been given of a case where the electronic mail which is generated by the connection issuance/mail generating means in which the transmitting/receiving device-side connection issuance/mail generating means 33 shown in FIG. 3 is target addressed transfer mail. Next, a description will be given of a case where the electronic mail generated by the connection issuance/mail generating means is target addressed mail.

In this case, the connection issuance/mail generating means is in particular referred to as connection issuance/target addressed mail generating means, means on the side of the mail transmitting/receiving device 6 is referred to as transmitting/receiving device-side connection issuance/target addressed mail generating means. That is, in this case, the transmitting/receiving device-side connection issuance/mail generating means 33 shown in FIG. 3 denotes transmitting/receiving device-side connection issuance/target addressed mail generating means.

That is, upon input of a signal which identifies a target actual address and data to-be-transmitted to request issuance of a connection ID and generation of target addressed mail, the transmitting/receiving device-side connection issuance/mail generating means 33 as transmitting/receiving device-side connection issuance/target addressed mail generating means identifies the target actual address, generates a signal requesting issuance of the connection ID, and inputs the signal into the connection issuance requesting means 32. The signal which identifies the target actual address and the data to-be-transmitted to request issuance of the connection identification indicator and generation of the target addressed mail is input, for example, from an input device 66 of the mail transmitting/receiving device 6.

Then, received is the template mail 92 which has been generated and transmitted by the mail server device 4 based on the connection issuance requesting mail 91 which has been generated and transmitted by the connection issuance requesting means 32. The text of the received template mail 92 is rewritten into the data to-be-transmitted and then replied. The thus transmitted electronic mail is the target addressed mail 93.

A description will be given of the transmitting/receiving device-side connection issuance/mail generation processing (FIG. 17, Step S74) in a case where the transmitting/receiving device-side connection issuance/mail generating means 33 shown in FIG. 3 is transmitting/receiving device-side connection issuance/target addressed mail generating means. The processing is referred to as transmitting/receiving device-side connection issuance/target addressed mail generation processing.

FIG. 19 is a flow chart which shows one example of procedures for the transmitting/receiving device-side connection issuance/target addressed mail generation processing. Hereinafter, a description will be given with reference to FIG. 19.

In this case, in the above described Step S72 (refer to FIG. 17), upon selection of the new connection/mail generating button 83 (refer to FIG. 18) of the connection list etc., display screen 80, the CPU 62 judges that the registered user has requested generation of connection issuance/target addressed mail, thereby executing storage processing of data to-be-transmitted etc., (Step S81).

In storage processing of the data to-be-transmitted etc., the CPU 62 requests input of a destination actual address of a target, data to-be-transmitted which is a text of electronic mail and data which is a subject of the electronic mail. Upon input, the CPU 62 temporarily stores the input data in the storage device (the main storage device 68 or the auxiliary storage device 70) of the mail transmitting/receiving device 6.

Next, the CPU 62 executes connection issuance requesting processing (Step S82).

The connection issuance requesting processing in Step S82 is processing in which based on a destination actual address stored in the above described storage device, the connection issuance requesting mail 91 (refer to FIG. 12) is generated and transmitted. It is the processing similar to the connection issuance requesting processing given in Step S73 (refer to FIG. 17).

The connection issuance requesting mail 91 (refer to FIG. 12) which has been generated and transmitted in the connection issuance requesting processing is received by the mail server device 4. New connection generation processing is executed in the mail server device 4 (FIG. 5, Step S5).

Upon receiving of the template mail 92 (refer to FIG. 12) which has been generated and transmitted in the new connection generation processing (FIG. 5, Step S5) (Step S83), the CPU 62 of the mail transmitting/receiving device 6 reads out the data to-be-transmitted which is a text of electronic mail and data which is a subject of the electronic mail temporarily stored in the above described storage device (Step S84), rewrites the template mail 92 based on the above described data read out from the storage device, and generates and transmits the target addressed mail 93 (refer to FIG. 13) (Step S85).

As described above, according to the transmitting/receiving device-side connection issuance/target addressed mail generation processing shown in FIG. 19, a series of processing from issuance and registration of new connection ID to generation and transmission of the target addressed mail can be executed by a single operation in the mail transmitting/receiving device 6 of the registered user.

The thus generated and transmitted target addressed mail 93 is subjected to expiration date extension processing (refer to FIG. 7) and header decode processing (refer to FIG. 8) in the mail server device 4, given as the target addressed transfer mail 94 (refer to FIG. 13) and transmitted to the target (FIG. 5, Step S6).

In each of the above described embodiments, a description has been given of a case where the mail transmitting/receiving device 6 of the registered user is provided with all the arrangements shown in FIG. 3. However, as described above, an arrangement of the mail transmitting/receiving device 6 of the registered user shall not be limited thereto, the present invention is also applicable, for example, to a case where the mail transmitting/receiving device 6 of the registered user is provided only with the mail client means 31, of all the arrangements shown in FIG. 3.

In this case, processing which generates and transmits the connection issuance requesting mail 91 (refer to FIG. 12) (that is, processing equivalent to processing for execution of the connection issuance requesting means 32 shown in FIG. 3) can be executed by the following method.

As a precondition of the processing, a user identification indicator of the registered user (that is, unID account 26 a) and a domain name which indicates the mail server device 4 (in this example, “unid.us”) are already known to the registered user.

In this case, the registered user uses the mail client means 31 of the mail transmitting/receiving device 6 to generate new electronic mail in which a destination actual address which is a target actual address, is given as a text, an electronic mail address having the unID account 26 a as a local part and a domain name of “unid.us” are given as a field value of a destination header, thereby transmitting the mail. This is received as the connection issuance requesting mail 91 by the mail server device 4.

As described above, in the mail server device 4 which has received the connection issuance requesting mail 91, the template mail 92 having the “x-unidto:” header (refer to FIG. 12) is generated and transmitted to a source actual address of the registered user. The mail client means 31 of the mail transmitting/receiving device 6 is used to reply to the template mail 92, thereby giving the target addressed mail 93 (refer to FIG. 13).

Hereinafter, receiving of a reply from a target, retransmission to the target, receiving of mail replied again from the target and others can be carried out by using only the mail client means 31 as described above.

Now, processing which generates and transmits the target addressed mail 93 (refer to FIG. 13) (that is, processing equivalent to processing executed by the target addressed mail generating means 34 shown in FIG. 3) can be executed by the following method.

As a precondition of this processing, a connection address which is used in electronic mail communications with the target is already known to the registered user.

For example, at first, the registered user uses the mail client means 31 of the mail transmitting/receiving device 6 to generate new electronic mail (it is acceptable that a text and a subject are kept blank) and transmit the electronic mail to the connection address. Since the electronic mail is free of the “x-unidto:” header, it is determined by the mail server device 4 to be the user addressed mail 95 (refer to FIG. 14) and the header encode processing (refer to FIG. 5, Step 12) is executed.

As a result, the user addressed transfer mail 96 (refer to FIG. 14) to which the “x-unidto:” header is added is generated in the mail server device 4 and transferred (returned) to the source actual address or the default actual address of the registered user.

The registered user uses the mail client means 31 of the mail transmitting/receiving device 6 to receive the mail and replies after the text and the subject are written. Then, this mail is given as the target addressed mail 93 (refer to FIG. 13).

Further, where the template mail 92 (refer to FIG. 12) transmitted from the mail server device 4 on new connection generation processing is retained in the mail client means 31 of the mail transmitting/receiving device 6 of the registered user, the mail client means 31 of the mail transmitting/receiving device 6 is used to reply to the template mail 92. Then, this is given as the target addressed mail 93.

As described so far, even where the mail transmitting/receiving device 6 is provided only with a general use mail client program (that is, the mail client means 31) devoid of functions to impart the “x-unidto:” header which is a dedicated header to electronic mail, it functions as the mail transmitting/receiving device 6 of the registered user which configures the electronic mail receiving system 2 of the present invention.

In each of the previously described embodiments, a description has been given of a case where whether or not electronic mail received by the mail server device 4 is target addressed mail or user addressed mail is judged by the fact that the “x-unidto:” header which is a dedicated header is provided or not. A reference has been also made to an arrangement in which judgment is made based on a field value of the source header (“from:” header) or a general header. However an arrangement can also be made in such a manner that whether the received electronic mail is target addressed mail or user addressed mail is judged by whether or not specific data acting as a mark (hereinafter referred to as “mark data”) is included in a field value of the header. Next, a description will be given of the thus arranged embodiment.

FIG. 21 is a drawing which describes processing content of the new connection generation processing in the embodiment. FIG. 22 is a drawing which describes processing content of the header decode processing in the embodiment. FIG. 23 is a drawing which describes processing content of the header encode processing in the embodiment.

An arrangement can also be made in such a manner that whether the mail is target addressed mail or user addressed mail is judged by whether the mark data is included in a field value of one of the headers or no mark is included in a field value of any headers. In this example, a description will be given of a case where judgment is made based on whether or not the mark data is included in a field value of a specific header. This is because judgment can be more quickly and easily made.

It is acceptable that the above described specific header is either a dedicated header or a general header. However, in this embodiment, a description will be given of a case where as the specific header, there is used a general header, in particular, a so-called standard general header. This is because the standard general header cannot be deleted by a general mail client program or a general mail server.

Further, here, a description will be given of a case where, of standard general headers, there is used a header which is not arbitrarily changed in general by a registered user or a target, for example, a case where an “In-Reply-To:” header is used as the above described specific header.

Where the received electronic mail is electronic mail which has been transmitted as a reply to or as being transferred from certain electronic mail (original electronic mail), that is, reply mail or transferred mail, the “In-Reply-To:” header is to identify the original electronic mail. In this embodiment, a header such as the “In-Reply-To:” header is from time to time referred to as a “reply original mail identification header” in a sense that it is a header for identifying electronic mail which is a source of a reply mail or transferred mail (hereinafter, may be simply referred to as “reply original mail”).

In general, as a field value of the “In-Reply-To:” header of reply mail or transferred mail, a field value of a “message-ID:” header of the above described original electronic mail (reply original mail) is transcripted. The “Message-ID:” header is a header for identifying each electronic mail. In this embodiment, a header such as the “Message-ID:” header is from time to time referred to as a “mail identification header.” It is noted that the “Message-ID:” header is also one of standard general headers.

In this embodiment, the “x-unidto:” header which is a dedicated header used in the previously described embodiment is not to be used and whether the electronic mail received by the mail server device 4 is target addressed mail or user addressed mail is judged with reference to whether or not the mark data is included in a field value of the “In-Reply-To:” header.

In the case of the above arrangement, a basic arrangement and processing content of the present system will be judged in a similar manner as a case where the mail is target addressed mail or user addressed mail with reference to the presence or absence of the “x-unidto:” header, with some points being different. Hereinafter, however, a description will be given of different points.

First, in the mail determination means 12 shown in FIG. 2, where the mark data is included in a field value of the “In-Reply-To:” header of the received electronic mail, the electronic mail is judged to be target addressed mail and where it is not included, the mail is judged to be user addressed mail.

In the decode means 17, on generation of target addressed transfer mail, the mark data is deleted from a field value of the “In-Reply-To:” header of the target addressed mail. It is noted that processing which generates the target addressed transfer mail based on the target addressed mail is from time to time referred to as “outbound transfer processing.”

In the encode means 14, on generation of user addressed transfer mail, the mark data is added to a field value of the “message-ID:” header of the user addressed mail. It is noted that processing which generates the user addressed transfer mail based on the user addressed mail is from time to time referred to as “inbound transfer processing.”

In the connection generation means 19, on generation of template mail, the mark data is added to a field value of the “message-ID:” header of connection issuance requesting mail.

In Step S2 shown in FIG. 5, the CPU 42 of the mail server device 4 judges whether or not the mark data is included in a field value of the “In-Reply-To:” header of the received electronic mail.

Where no mark data is included in the field value of the “In-Reply-To:” header, processing is executed in a similar manner as a case where no “x-unidto:” header is provided in the previously described embodiment. Where the mark data is included in the field value of the “In-Reply-To:” header, processing is executed in a similar manner as a case where the “x-unidto:” header is provided in the previously described embodiment.

FIG. 21 illustrates an arrangement of connection issuance requesting mail 191 which has been transmitted from the mail transmitting/receiving device 6 of the registered user and arrangement of template mail 192 which has been transmitted from the mail server device 4.

In the new connection generation processing shown in FIG. 6, on generation of template mail, the mark data is added to a field value of the “message-ID:” header of the connection issuance requesting mail 191 and used as a field value of the “message-ID:” header. In this example, such that a character string of “x-unidto.” is added as the mark data before a field value of the “message-ID:” header of the connection issuance requesting mail 191 is given as a field value of the “message-ID:” header of the template mail.

As described above, the template mail 192 which has been transmitted from the mail server device 4 is transmitted to a source actual address of the mail transmitting/receiving device 6 of a registered user. The registered user who has received the template mail 192 rewrites the text and replies and, this is given as target addressed mail. Upon reply, the field value of the “message-ID:” header of the template mail is transcripted as a field value of the “In-Reply-To:” header of the target addressed mail.

FIG. 22 illustrates an arrangement of target addressed mail 193 replied from the mail transmitting/receiving device 6 of the registered user and an arrangement of target addressed transfer mail 194.

Of the header decode processing shown in FIG. 8, in basic header decode processing (Step S41), the mark data is deleted from the field value of the “In-Reply-To:” header of the received target addressed mail 193 (refer to FIG. 22). And, this is given as a field value of the “In-Reply-To:” header of the target addressed transfer mail 194.

Then, a header name of a “to:” header of the target addressed mail 193 is changed to “from:” and added is the “to:” header in which a field value is a destination actual address 27 d. In this embodiment, irrespective of what is a reply source actual address which is an actual source of user addressed mail, as a field value of the “to:” header of target addressed transfer mail which is a reply to the user addressed mail, there is used a destination actual address 27 d registered in the connection table 27. That is, in this embodiment, only the destination actual address corresponds to the above described target actual address.

According to the above described arrangement, for example, even where target addressed transfer mail is illegally acquired by a third party and user addressed mail is transmitted to the registered user from an electronic mail address of the third party, a reply to the user addressed mail from the registered user is transmitted to the destination actual address 27 d registered in the connection table 27. Therefore, fraud can be found earlier to prevent damage from spreading.

Then, where a reply source actual address of the user addressed mail is an electronic mail address other than the destination actual address 27 d registered in the connection table 27, an arrangement is made in such a manner that the reply source actual address is added to a part of the user addressed transfer mail, for example, to a first line of the text.

The above arrangement has been made, with consideration given to such a possibility that a target who has received the target addressed transfer mail may reply from an electronic mail address other than the destination actual address 27 d registered in the connection table 27. Further, the above arrangement makes it possible to promote awareness of a registered user who has received the user addressed transfer mail.

In the basic header decode processing shown in FIG. 8, there is no change in field value of the “message-ID:” header.

In this embodiment, of the header decode processing shown in FIG. 8, processing related to the “cc:” header (Step S42 and Step S43) is not executed.

FIG. 23 illustrates an arrangement of user addressed mail 195 replied from the mail transmitting/receiving device 6 of a target to the target addressed transfer mail 194 and an arrangement of user addressed transfer mail 196.

Of the header encode processing shown in FIG. 9, in basic header encode processing (Step S52), the mark data is added to a field value of the “message-ID:” header of the received user addressed mail 195 (refer to FIG. 23), which is used as a field value of the “message-ID:” header of the user addressed transfer mail 196.

In the basic header encode processing, the “In-Reply-To:” header is not changed in field value.

In this embodiment, of the header encode processing shown in FIG. 9, processing related to the “cc:” header (Step S53 and Step S54) is not executed.

When the target addressed transfer mail 194 shown in FIG. 22 is replied from the mail transmitting/receiving device 6 of a target, a field value of the “message-ID:” header of the target addressed transfer mail 194 is transcripted as a field value of the “In-Reply-To:” header of the user addressed mail 195. This is similar to a case of reply to the above described template mail 192.

A registered user who has received the user addressed transfer mail 196 rewrites the text thereof. Electronic mail retransmitted (that is, replied to the target) is also handled as target addressed mail and processed in a similar manner as the above described target addressed mail 193 (refer to FIG. 22).

In reply to a target with regard to the user addressed transfer mail 196, a field value of the “message-ID:” header of the user addressed transfer mail 196 is transcripted as a field value of the “In-Reply-To:” header of the target addressed mail 193. This is similar to a case of a reply to the above described target addressed transfer mail 194.

Now, in this embodiment, a series of electronic mail exchanged between the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target is arranged to display a so-called thread in which, for example, a correlation (parent-child relationship) of reply or transfer is listed in a tree structure on the display device 64 of the mail transmitting/receiving device 6.

FIG. 31A is a drawing which shows one example of a thread which is normally displayed on the mail transmitting/receiving device 6 of the registered user. FIG. 31B is a drawing which shows one example of a thread which is normally displayed on the mail transmitting/receiving device 6 of the target.

There are available various methods for displaying the thread. However, in this embodiment, a description will be given of a case where a “References:” header is used.

Where the received electronic mail is reply mail or transferred mail, the “References:” header is a header for identifying the reply original mail of reply mail or transferred mail (original electronic mail) and where the reply original mail is reply mail or transferred mail, the “References:” header is a header for sequentially describing identification of the reply original mail of the received electronic mail in a retrospective manner so as to identify reply original mail of the reply original mail concerned and so on. In this embodiment, a header such as the “References:” header is from time to time referred to as a “reply original mail identification history header.”

In general, as a field value of the “References:” header of the reply mail or transferred mail, a field value of the “In-Reply-To:” header of the reply mail or transferred mail is added in a sequential manner.

As described above, as a field value of the “In-Reply-To:” header, a field value of the message-ID:” header of the reply original mail is transcripted. Thus, in the end, as a field value of the “References:” header, field values of the “message-ID:” header of each reply original mail up to the electronic mail concerned are to be enlisted in a sequential manner.

FIG. 29 is a drawing which describes a situation on the assumption that in this embodiment, without executing special processing to be described later, electronic mail (hereinafter, may be referred to as “message”) is replied repeatedly between the mail transmitting/receiving device 6 of the target and the mail transmitting/receiving device 6 of the registered user. FIG. 29 is also a drawing which describes description content of headers of messages at each step of transmission and receiving of electronic mail.

In FIG. 29, for the sake of description, of data which configures messages at each stage of processing (hereinafter may be referred to as “message data”), only the “message-ID:” header, the “In-Reply-To:” header and the “References:” header are described.

FIG. 29 shows an example in which messages have been transmitted to and received from three times continuously from a message of the uppermost right side to a message of the lowermost right side between the mail transmitting/receiving device 6 of the target and the mail transmitting/receiving device 6 of the registered user. In this example, for the sake of description, field values of the “message-ID:” header of the user addressed mail are given in sequence as “A,” “B” and “C,” whereas field values of the “message-ID:” header of the target addressed mail are given in sequence as “1,” “2” and “3,” with the mark data given as “X.”

Therefore, message data of the message of the uppermost right side given in FIG. 29 (equivalent to “user addressed mail”) is expressed as follows:

message-ID: A

In-Reply-To: <null>

References: <null>

Message data of the message of the uppermost left side given in FIG. 29 (equivalent to “user addressed transfer mail”) acquired by subjecting the user addressed mail to the basic header encode processing is expressed as follows:

message-ID: XA

In-Reply-To: <null>

References: <null>

Message data of the message of the second-stage left side given in FIG. 29 (equivalent to “target addressed mail”) generated as reply mail to the user addressed transfer mail is expressed as follows:

message-ID: 1

In-Reply-To: XA

References: XA

Message data of the message of the second-stage right side given in FIG. 29 (equivalent to “target addressed transfer mail”) acquired by subjecting the target addressed mail to the basic header decode processing is expressed as follows:

message-ID: 1

In-Reply-To: A

References: XA

Further, message data of the message of the third-stage right side given in FIG. 29 (equivalent to “user addressed mail”) generated as reply mail to the target addressed transfer mail is expressed as follows:

message-ID: B

In-Reply-To:1

References: XA, 1

The similar processing is repeated hereinafter. As a result, the mail transmitting/receiving device 6 of the target on the right side of FIG. 29 stores three transmitted messages (user addressed mail) with respective field values of the “message-ID:” header of “A,” “B” and “C” and three received messages (target addressed transfer mail) with respective field values of the “message-ID:” header of “1,” “2” and “3,” a total of six messages.

On the other hand, the mail transmitting/receiving device 6 of the registered user on the left side of FIG. 29 stores three received messages (user addressed transfer mail) with respective field values of the “message-ID:” header of “XA,” “XB” and “XC,” and three transmitted messages (target addressed mail) with respective field values of the “message-ID:” header of “1,” “2” and “3,” a total of six messages.

In this embodiment, for the sake of description, such an expression is from time to time made that field values of the “message-ID:” header are used to identify a message. According to this expression, for example, messages in which field values of the “message-ID:” header are given as “A,” “XA” and “1” are respectively expressed as a message “A,” a message “XA” and a message “1.”

Now, a thread expression in the mail transmitting/receiving device 6 of the registered user upon complete transmission of the message “3” described at the lowermost stage left side in FIG. 29 is made according to field values of the “References:” header and those of the “message-ID:” header of the message. That is, six messages stored in the mail transmitting/receiving device 6 of the registered user are displayed in the order of a message “XA,” a message “1,” a message “XB,” a message “2,” a message “XC” and a message “3.” Then, the thread is made up of these messages.

The thus displayed thread is to be expressed, for example, as shown in FIG. 31A. The thread is displayed in a mode which is able to tell a parent-child relationship of each message with which the thread is made up. In this example, a reply message (child message) to a message (parent message) is displayed by being placed on the right side so as to deviate from the parent message.

According to FIG. 31A, it is found that a reply to the message “XA” is the message “1,” a reply to the message “1” is the message “XB,” in sequence, a reply to the message “XC” is the message “3.”

On displaying the thread, there are no special restrictions for what data of each message is to be displayed. However, for example, a “subject” and/or a “text” of each message can be displayed as data of each message which configures the thread.

Next, an evaluation will be given of display of the thread in the mail transmitting/receiving device 6 of the target upon completely receiving of the message “3” described on the lowermost right side in FIG. 29.

Field values of the “References:” header of the message “3” stored in the mail transmitting/receiving device 6 of the target are the same as the field values of the “References:” header of the message stored in the mail transmitting/receiving device 6 of the registered user, that is, “XA, 1, XB, 2, XC.” A field value of the “message-ID:” header is “3.” However, as described above, the messages stored in the mail transmitting/receiving device 6 of the target are the message “A,” the message “B,” the message “C,” the message “1,” the message “2” and the message “3,” but the message “XA,” the message “XB” and the message “XC” are not stored.

As described above, the message “XA,” the message “XB” and the message “XC” stored in the mail transmitting/receiving device 6 of the registered user are those in which the mark data “X” is added to the field values of the “message-ID:” header by the above described basic header encode processing. They are substantially the same messages as the message “A,” the message “B” and the message “C” respectively which are stored in the mail transmitting/receiving device 6 of the target.

Although they are substantially the same messages, if each of which is different in field value of the “message-ID:” header, they are judged to be a different message. Thus, in the mail transmitting/receiving device 6 of the target, there is found a disadvantage that a message identified by a field value of the “References:” header does not exist in actually stored message, that is, a disadvantage that a message identified by a field value of the “References:” header does not conform to an actually stored message. Thus, there is a fear that the thread may not be normally displayed as it is.

Therefore, in this embodiment, such an arrangement is made that special processing is executed for avoiding the above described disadvantage, that is, both in the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target, such processing is executed that field values of the “References:” header are respectively adjusted so as to conform to the actually stored messages (this processing is referred to as “reply original mail identification history header adjustment processing”).

FIG. 30 is a drawing which describes a situation that while the reply original mail identification history header adjustment processing is executed, messages are transmitted to and received from repeatedly between the mail transmitting/receiving device 6 of the target and the mail transmitting/receiving device 6 of the registered user. This is a drawing corresponding to FIG. 29.

In an example shown in FIG. 30, such an arrangement is made that References retention processing is executed each time prior to the basic header encode processing and the basic header decode processing, and References restoration processing is also executed each time after the basic header encode processing and the basic header decode processing. The References retention processing and References restoration processing correspond to the reply original mail identification history header adjustment processing.

That is, in the example shown in FIG. 30, both of the header encode processing and the header decode processing are arranged so as to include the reply original mail identification history header adjustment processing.

FIG. 24 is a flow chart which shows one example of the References retention processing which configures the reply original mail identification history header adjustment processing. FIG. 25 is a flow chart which shows one example of the References restoration processing which configures the reply original mail identification history header adjustment processing. FIG. 26 is a drawing which shows one example of data arrangement of the References table 28 used in the reply original mail identification history header adjustment processing.

A description will be given of the reply original mail identification history header adjustment processing based on FIG. 24 to FIG. 26 and FIG. 30. As shown in FIG. 30, the References retention processing is executed each time prior to the basic header encode processing and the basic header decode processing.

As shown in FIG. 24, in the References retention processing, field values of the “message-ID:” header and field values of the “References:” header of a received message are mutually associated to give a record. And the record is retained in the References table 28 which configures the database 25 (Step S101).

As shown in FIG. 30, after the References retention processing, the basic header encode processing and the basic header decode processing are individually executed. Subsequently, each of the processing is subjected to the References restoration processing.

As shown in FIG. 25, in the References restoration processing, at first, a field value of the “In-Reply-To:” header is stored as a variable IRT (Step S102).

Next, from data retained in the References table 28, there is extracted a record in which the field value of the “message-ID:” header is equal in value to the variable IRT (Step S103).

In Step S103, where a corresponding record is found, a field value of the “References:” header of the record concerned is set as a field value of the “References:” header of the message concerned (Step S104).

In Step S103, where a corresponding record is not found, “null” is set as a field value of the “References:” header of the message concerned (Step S104).

Next, the same value as the variable IRT is added to the field value of the “References:” header of the message concerned (Step S105).

FIG. 27 is a drawing which describes transition of message data in the reply original mail identification history header adjustment processing executed in the header encode processing. FIG. 28 is a drawing which describes transition of message data in the reply original mail identification history header adjustment processing executed on the header decode processing.

As shown in FIG. 27, in the reply original mail identification history header adjustment processing executed in the header encode processing, the message data undergoes transition from message data 110 to message data 113.

The message data 110 is message data before and after execution of the References retention processing (Step S101). The message data 111 is message data after execution of the basic header encode processing (Step S52). The message data 112 is message data after execution of Step S104 in the References restoration processing. The message data 113 is message data after execution of Step S105 in the References restoration processing.

As shown in FIG. 28, in the reply original mail identification history header adjustment processing executed on the header decode processing, message data undergoes transition from message data 114 to message data 117.

The message data 114 is message data before and after the References retention processing (Step S101). The message data 115 is message data after execution of the basic header decode processing (Step S41). The message data 116 is message data after execution of Step S104 in the References restoration processing. The message data 117 is message data after execution of Step S105 in the References restoration processing.

As shown in FIG. 30, the reply original mail identification history header adjustment processing is executed, by which field values of the “References:” header of the message “3” stored in the mail transmitting/receiving device 6 of the target are given as “A, 1, B, 2, C” and conformable to the message “A,” the message “B,” the message “C” the message “1” and the message “2” stored in the mail transmitting/receiving device 6 of the target.

Further, field values of the “References:” header of the message “3” stored in the mail transmitting/receiving device 6 of the registered user are given as “XA, 1, XB, 2, XC” and conformable to the message “XA,” the message “XB,” the message “XC,” the message “1” and the message “2” which are stored in the mail transmitting/receiving device 6 of the registered user.

As described above, this embodiment is arranged in such a manner that the reply original mail identification history header adjustment processing is executed in the header encode processing and the header decode processing. Therefore, both in the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target, the respective field values of the “References:” header are conformable to the actually stored messages. As a result, the thread is normally displayed both in the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target (refer to FIG. 31A and FIG. 31B).

In this embodiment, a description has been given of the example which is arranged in such a manner that the reply original mail identification history header adjustment processing is configured with the References retention processing and the References restoration processing, the References retention processing is executed each time prior to the basic header encode processing and the basic header decode processing, and the References restoration processing is executed each time after the basic header encode processing and the basic header decode processing. However, the reply original mail identification history header adjustment processing shall not be limited to the above described arrangement.

The reply original mail identification history header adjustment processing may be expressed as follows:

The reply original mail identification history header adjustment processing is such processing that in the header encode processing (more commonly, inbound transfer processing), field values of the “In-Reply-To:” header (reply original mail identification header) of the user addressed transfer mail 113, that is, field values of the “message-ID:” header (mail identification header) of the target addressed mail 118, are added to field values of the “References:” header (reply original mail identification history header) of target addressed mail 118 corresponding to reply original mail of user addressed transfer mail 113, and thus obtained results are given as the field values of the “References:” header of the user addressed transfer mail 113, and in the header decode processing (more commonly, outbound transfer processing), field values of the “In-Reply-To:” header of the target addressed transfer mail 117, that is, field values of the “message-ID:” header of the user addressed mail 110 are added to field values of the “References:” header of user addressed mail 110 corresponding to reply original mail of target addressed transfer mail 117, and the thus obtained results are given as field values of the “References:” header of the target addressed transfer mail 117.

Further, the reply original mail identification history header adjustment processing shall not be limited to the above described processing. In brief, the processing may be such that in the header encode processing (more commonly, inbound transfer processing) and/or the header decode processing (more commonly, outbound transfer processing), the respective field values of the “References:” header are adjusted so as to be conformable to the actually stored messages both in the mail transmitting/receiving device 6 of the registered user and the mail transmitting/receiving device 6 of the target.

In each of the above described embodiments, a description has been given of a case where each of the mail server device and the mail transmitting/receiving device is arranged with one computer. The present invention shall not be, however, limited thereto. It is acceptable that the mail server device is made up of two or more computers. In this case, it is possible to connect the two or more computers via the above described information communication means 8.

Further, the mail transmitting/receiving device can be configured with two or more computers. In this case as well, it is possible to connect the two or more computers via the information communication means 8.

FIG. 20 is a block diagram which shows an example in which a mail transmitting/receiving device 106 is configured with two or more computers. The mail transmitting/receiving device 106 is provided with a terminal device 7 and a web server 5.

A hardware arrangement of the terminal device 7 is similar to that of the mail transmitting/receiving device 6 shown in FIG. 4. A hardware arrangement of the web server 5 is similar to that of the mail server device 4 given in FIG. 4 where the web server is configured with one computer. Where the web server 5 is configured with two or more computers, an arrangement of each computer is similar to that of the mail server device 4 shown in FIG. 4.

For example, the terminal device 7 is able to communicate with the web server 5 via the information communication means 8. Where the web server 5 is configured with two or more computers, these computers are able to communicate with each other, for example, via the information communication means 8.

The terminal device 7 is provided with a web browser 3.

FIG. 20 shows a state in which a registered user logs onto a web page dedicated to the registered user (hereinafter, referred to as “dedicated page”) on the web server 5 via the web browser 3 of the terminal device 7.

In this state, the web server 5 is arranged so as to give similar functions as those of the mail processing portion 30 and the local database 35 of the mail transmitting/receiving device 6 shown in FIG. 3. Of constituents of the web server 5 shown in FIG. 20, those having similar functions as the constituents of the mail transmitting/receiving device 6 shown in FIG. 3 are given the same reference numerals. As a matter of course, the local database 35 is made up of only data related to the registered user concerned.

That is, in the mail transmitting/receiving device 106, functions corresponding to the mail processing portion 30 and the local database 35 of the mail transmitting/receiving device 6 are provided from the web server 5 in an ASP (Application Service Provider) method.

In other words, in a state that the registered user logs onto a dedicated page of the registered user, on execution of the above described mail processing (refer to FIG. 17 and FIG. 19), the mail transmitting/receiving device 106 made up of the terminal device 7 and the web server 5 is a device which is equivalent to the mail transmitting/receiving device 6 shown in FIG. 3.

The mail transmitting/receiving device 106 is used in the following manner. Here, it is assumed that an identification indicator (hereinafter, referred to as “log-in ID”) and a log-in password are given in advance in order to log onto the dedicated page of the registered user.

The registered user inputs the log-in ID and the log-in password via the web browser 3 of the terminal device 7, by which the user is able to log onto the dedicated page of the registered user.

When the registered user logs onto the dedicated page, a dedicated page is displayed on a display device of the terminal device 7 of the registered user. The dedicated page is similar to, for example, a connection list etc., display screen 80 shown in FIG. 18.

The registered user performs operation (click or tap) for the dedicated page via the web browser 3 of the terminal device 7, by which mail processing similar to that by the mail transmitting/receiving device 6 is executed by the web server 5. The processing progress and results are displayed via the web browser 3 of the terminal device 7 on the display device.

As described so far, the terminal device 7 of the registered user and the web server 5 are integrated to configure the mail transmitting/receiving device 106 of the registered user. The registered user is not aware of the existence of the web server 5 and able to perform operation as if the terminal device 7 itself would be the above described mail transmitting/receiving device 6.

An arrangement shown in FIG. 20 is illustrated as the mail transmitting/receiving device 106 which is based on the ASP method, however, the arrangement of the mail transmitting/receiving device 106 shall not be limited thereto. For example, in FIG. 20, all functions of the mail processing portion 30 and the local database 35 of the mail transmitting/receiving device 106 are arranged so as to be executed at the web server 5. It is, however, also possible that these functions are arranged so as to be processed in collaboration with the web server 5 and the terminal device 7.

For example, an arrangement can be made in such a manner that, of the mail processing portion 30, mail client means 31 is installed on the terminal device 7, while other means are installed on the web server 5.

Even in the case of the above arrangement, in a state of logging onto the dedicated page of the registered user, the mail transmitting/receiving device 106 made up of the terminal device 7 and the web server 5 is a device equivalent to the mail transmitting/receiving device 6 in terms of executing the above described mail processing.

The target is also able to transmit and receive electronic mail by using the mail transmitting/receiving device (for the sake of convenience, this is also referred to as the mail transmitting/receiving device 106) which is similar to the mail transmitting/receiving device 106. However, means other than the mail client means 31 are not required in the mail processing portion 30 of the mail transmitting/receiving device 106 of the target.

Further, in the electronic mail communication system 2, both the registered user and the target are able to use the mail transmitting/receiving device 106 or one of them is able to use the mail transmitting/receiving device 106 and the other is able to use the mail transmitting/receiving device 6. Furthermore, they may use any one of the mail transmitting/receiving device 106 and the mail transmitting/receiving device 6, depending on the situation.

Step S1 shown in FIG. 5 corresponds to the mail receiving means 11 which configures the transfer processing portion 10 of the mail server device 4 given in FIG. 2. Step S2 to Step S4 correspond to the mail determination means 12. Step S5 corresponds to the connection generation means 19. Step S7 corresponds to the expiration date update means 16. Step S8 corresponds to the decode means 17. Step S9 to Step S10 correspond to the validity determination means 13. Step S11 corresponds to the error mail transmitting means 18. Step S12 corresponds to the encode means 14.

Step S61 to Step S63 shown in FIG. 10 correspond to the connection generation/decode means 20. Then, Step S6 shown in FIG. 5 and Step S64 shown in FIG. 10 correspond to the mail transmitting means 15.

Step S71 shown in FIG. 17 corresponds to the connection list etc., displaying means 39 which configures the mail processing portion 30 of the mail transmitting/receiving device 6 given in FIG. 3 or the mail transmitting/receiving device 106 given in FIG. 20. Step S73 corresponds to the connection issuance requesting means 32. Step S75 corresponds to the target addressed mail generating means 34.

Step S74 shown in FIG. 17 (including Step S81 to Step S85 shown in FIG. 19) corresponds to the transmitting/receiving device-side connection issuance/mail generating means 33.

In this embodiment, as a record medium which stores programs on the side of the mail server device 4 of the electronic mail communication system 2 and as a record medium which stores programs on the side of the mail transmitting/receiving device 106, there is illustrated a hard disk attached to a HDD. As a record medium which stores programs on the side of the mail transmitting/receiving device 6, there is illustrated a flash memory attached to a SSD. However, a record medium which stores programs shall not be limited thereto. A record medium which stores programs includes, for example, an external memory card, a CD-ROM, a DVD-ROM, a flexible disk and an electromagnetic tape. A main storage device can also be used as a record medium which stores programs.

There are no particular restrictions on a distributing mode of a program. The program may be distributed in a state that the program is stored in a record medium or the program may be distributed via wire or wireless information communication means.

There are no particular restrictions on a recording mode of a program. The program may be stored in a record medium or distributed so as to be directly executed. Alternatively, for example, the program may be stored in a record medium or distributed in a state of compression so as to be used after decompression.

In each of the above described embodiments, a description has been given of a case where a computer is used to realize each of the functions shown in FIG. 2 and FIG. 3 or FIG. 20. However, it is also acceptable that a part or a whole of the functions may be configured by using hardware logic.

Further, the above described block diagrams, arrangements of hardware, flowcharts, arrangements of database, arrangements of electronic mail etc., are only examples. The present application shall not be, however, limited thereto.

The electronic mail communication system according to the first invention as claimed in the present application is an electronic mail communication system which is provided with a plurality of mail transmitting/receiving devices, each of which has a mail processing portion having functions to transmit and receive electronic mail, and a mail server device which is capable of communicating with the mail transmitting/receiving device via information communication means, in which the mail server device is provided with a database which stores a target actual address which is an electronic mail address of a target for transmitting electronic mail and a user actual address which is an electronic mail address of a registered user for receiving electronic mail replied from the target in association with a connection identification indicator corresponding to a connection address which is a temporary electronic mail address of the registered user and an electronic mail address under the control of the mail server device, and a transfer processing portion which executes transfer processing of electronic mail based on data stored in the database, and the transfer processing portion is provided with mail receiving means which receives electronic mail from the mail transmitting/receiving device via the information communication means, mail determination means which determines whether the electronic mail received by the mail receiving means is target addressed mail to be transmitted from the registered user to the target or user addressed mail to be transmitted from the target to the registered user based on header information of the electronic mail, decode means which generates target addressed transfer mail which is electronic mail in which a field value of a destination header indicating a destination of the target addressed mail is given as the target actual address and a field value of a source header indicating a source is given as a connection address corresponding to the connection identification indicator, where the mail determination means determines that the electronic mail is the target addressed mail, encode means which generates user addressed transfer mail in which a field value of a destination header of the user addressed mail is given as the user actual address, that is, user addressed transfer mail in which a text of the user addressed transfer mail is rewritten in the mail transmitting/receiving device which has received the user addressed transfer mail and replied to give the target addressed mail, where the mail determination means determines that the electronic mail is the user addressed mail, and mail transmitting means which transmits electronic mail generated in the decode means or the encode means via the information communication means according to the header information of the electronic mail.

Therefore, a field value of the source header of the target addressed mail transmitted from the registered user is rewritten into a connection address corresponding to a connection identification indicator to generate target addressed transfer mail and the mail is transmitted to a target. Where the target who has received the target addressed transfer mail replies, a field value of a destination header of the user addressed mail which has been replied is rewritten into the user actual address to generate user addressed transfer mail and the mail can be transferred to the registered user.

For this reason, if the target actual address is known, the registered user of the system stores in the database the target actual address and the personal user actual address in association with a connection identification indicator. It is, thereby, possible to transmit and receive electronic mail with any target who does not have a membership registration of the system, without disclosure of the personal user actual address to the target.

Further, the connection identification indicator corresponding uniquely to the connection address can be generated for each target actual address or can be generated for each purpose even in a case of the same target actual address.

For this reason, with regard to a target or a purpose for which information exchange by electronic mail is no longer needed, only a connection identification indicator corresponding thereto may be discharged. Thus, acceptance or rejection of mail for each target or each purpose can be controlled easily.

That is, it is possible to transmit and receive electronic mail with a target who does not have a membership registration without disclosure of a personal electronic mail address. Thus, it is also possible to realize an electronic mail communication system which is easy in controlling the acceptance or rejection of mail.

Further, the user addressed transfer mail is arranged in such a manner that a text thereof is rewritten by the mail transmitting/receiving device which has received the user addressed transfer mail and replied, which is then given as target addressed mail.

Therefore, a general mail client program which is installed in the mail transmitting/receiving device of a registered user is used to rewrite the text of the received user addressed transfer mail and to perform reply operation, thus making it possible to retransmit target addressed mail to a target (reply to the target).

For this reason, it is possible to exchange electronic mail easily and any times by using a mail transmitting/receiving device having a general mail client program with a target who does not have a membership registration without disclosure of a personal electronic mail address.

The electronic mail communication system according to the second invention as claimed in the present application is the electronic mail communication system according to the first invention as claimed in the present application in which the encode means is arranged in such a manner that a field value of the source header of the user addressed transfer mail is given as the connection address.

Therefore, where a registered user replies to the received user addressed transfer mail to retransmit target addressed mail to a target (reply to the target), the retransmitted target addressed mail is inevitably transmitted via the mail server device concerned, irrespective of a mail server designated by the mail client program of the mail transmitting/receiving device of the registered user which is used for retransmission.

For this reason, on retransmission of the target addressed mail, the registered user is able to exchange electronic mail easily through any given personal electronic mail address (that is, mail account) with a target having no membership registration without disclosure of the personal electronic mail address by using the mail transmitting/receiving device with a general mail client program installed.

Further, the field value of the source header of the target addressed transfer mail and the field value of the source header of the user addressed transfer mail are given as the same connection address. Therefore, with regard to both the user addressed mail replied to the target addressed transfer mail and the target addressed mail replied to the user addressed transfer mail, an electronic mail address thereof to be transmitted is the same connection address.

For this reason, as compared with a case that each of the user addressed mail and the target addressed mail is controlled separately with an electronic mail address to be transmitted, the electronic mail address can be controlled easily. As a result, acceptance or rejection of mail for each target or each purpose can be controlled more easily.

The electronic mail communication system according to the third invention as claimed in the present application is the electronic mail communication system according to the first or the second invention as claimed in the present application, in which the mail determination means is further arranged so as to determine whether or not the electronic mail received by the mail receiving means is connection issuance requesting mail in which a registered user identifies the target actual address to request the mail server device for issuing a connection identification indicator based on header information of the electronic mail, the transfer processing portion is further provided with connection generation means in which where the mail determination means determines that the electronic mail is connection issuance requesting mail, a new connection identification indicator is issued, a target actual address identified by the connection issuance requesting mail and the user actual address identified by the connection issuance requesting mail or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is generated template mail which is electronic mail having the written user actual address as a field value of the destination header and template mail which is given as the target addressed mail when a text of the template mail is rewritten and replied in the mail transmitting/receiving device which has received the template mail, and the mail transmitting means is further arranged so as to transmit the electronic mail generated by the connection generation means via the information communication means according to the header information of the electronic mail.

Therefore, the registered user only transmits the connection issuance requesting mail with the identified target actual address to the mail server device, by which the new connection identification indicator is automatically issued. And, the target actual address and the user actual address are stored in the database in association with the new connection identification indicator.

Further, since the template mail is transmitted from the mail server device to the user actual address, the registered user who has received the template mail only rewrites a text of the template mail into a content which is desired to be transmitted to a target and performs reply operation, thus making it possible to transmit the target addressed mail. For this reason, first target addressed mail to the target can also be transmitted by using a mail transmitting/receiving device with a general mail client program installed.

The electronic mail communication system according to the fourth invention as claimed in the present application is the electronic mail communication system according to the third invention as claimed in the present application, in which the mail processing portion of the mail transmitting/receiving device is further provided with connection issuance requesting means in which upon input of a signal which identifies the target actual address to request issuance of the connection identification indicator, the connection issuance requesting mail is generated and transmitted to the mail server device via the information communication means, and transmitting/receiving device-side connection issuance/target addressed mail generating means in which, upon input of a signal which identifies the target actual address and data to-be-transmitted to request issuance of the connection identification indicator and generation of target addressed mail, a signal which identifies the target actual address to request issuance of the connection identification indicator is input into the connection issuance requesting means, there is received the template mail generated and transmitted by the mail server device based on the connection issuance requesting mail generated and transmitted by the connection issuance requesting means, and a text of the thus received template mail is rewritten into the data to-be-transmitted and replied.

Therefore, the registered user only identifies the target actual address and data to-be-transmitted and inputs into the mail transmitting/receiving device a signal which requests issuance of the connection identification indicator and generation of the target addressed mail, by which the new connection identification indicator is automatically issued at the mail server device. And, the target actual address and the user actual address are stored in the database in association with the new connection identification indicator. Further, the target addressed mail in which the data to-be-transmitted is given as a text is automatically generated and transmitted in the mail transmitting/receiving device.

For this reason, even if the mail server device is devoid of dedicated processing functions, the mail transmitting/receiving device is able to perform a series of processing from issuance and registration of the new connection identification indicator to generation and transmission of the target addressed mail by single operation.

The electronic mail communication system according to the fifth invention as claimed in the present application is the electronic mail communication system according to any one of the first to the third invention as claimed in the present application, in which the transfer processing portion is further provided with connection generation/decode means in which a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted is received from the mail transmitting/receiving device of the registered user via the information communication means to issue a new connection identification indicator, the target actual address identified by the requesting signal and the user actual address identified by the requesting signal or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is further generated electronic mail in which a field value of the destination header is given as the target actual address, a field value of the source header is given as a connection address corresponding to the new connection identification indicator and a text is given as the data to-be-transmitted, and the mail transmitting means is further arranged in such a manner that the electronic mail generated by the connection generation/decode means is transmitted via the information communication means according to the header information of the electronic mail.

Therefore, the registered user only transmits the connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and the data to-be-transmitted from the mail transmitting/receiving device to the mail server device, by which the new connection identification indicator is issued automatically in the mail server device. And, the target actual address and the user actual address are stored in the database in association with the new connection identification indicator. Further, electronic mail similar to the target addressed transfer mail which is generated in the decode means is generated and transmitted to the target actual address.

For this reason, a program which generates and transmits the connection issuance/target addressed transfer mail generation requesting signal is installed on the mail transmitting/receiving device, by which it is able to perform a series of processing from issuance and registration of the new connection identification indicator to generation and transmission of the electronic mail similar to the target addressed transfer mail by single operation in the mail transmitting/receiving device.

The electronic mail communication system according to the sixth invention as claimed in the present application is the electronic mail communication system according to any one of the first to the fifth invention as claimed in the present application, in which the database further stores an expiration date of the connection identification indicator set for each connection identification indicator, and the transfer processing portion is further provided with validity determination means in which where the mail determination means determines that the electronic mail is the user addressed mail, determination is made for whether or not an expiration date of the connection identification indicator corresponding to the user addressed mail has expired based on data stored in the database, and where the expiration date is determined not to have expired, control of the user addressed mail is shifted to the encode means, and error mail transmitting means in which where the validity determination means determines that the expiration date has expired, electronic mail to the effect that the user addressed mail has been erroneously transmitted is transmitted to a source of the user addressed mail.

Therefore, the expiration date is set for the connection identification indicator, by which after elapse of the expiration date, unwanted electronic mail from a target can be automatically blocked.

Further, any given expiration date is set for each connection identification indicator, thus making it possible to make the expiration date different depending on a relationship with a target and a purpose. For this reason, it is possible to control the acceptance or rejection of electronic mail by simple operation in a more thoughtful manner.

The electronic mail communication system according to the seventh invention as claimed in the present application is the electronic mail communication system according to the sixth invention as claimed in the present application, in which the database further stores information on whether or not the expiration date of the connection identification indicator set for each connection identification indicator is automatically updated, the transfer processing portion is further provided with expiration date update means in which where the mail determination means determines that the electronic mail is target addressed mail, determination is made for whether or not the expiration date of the connection identification indicator corresponding to the target addressed mail is automatically updated based on data stored in the database, where the expiration date is determined to be updated, the expiration date of the connection identification indicator stored in the database is updated, and where the expiration date is determined not to be updated, the expiration date of the connection identification indicator stored in the database is not updated.

Therefore, the expiration date of the connection identification indicator is set so as to be automatically updated. It is, thereby, possible to automatically extend the expiration date of the connection identification indicator only where electronic mail is transmitted from a registered user to a target.

For this reason, where electronic mail is transmitted from a target one-sidedly, the expiration date is not extended. After elapse of the expiration date, unwanted electronic mail from the target is automatically blocked, while, for example, where it is necessary to transmit electronic mail from a registered user to a target and wait for the reply, the expiration date is automatically extended, thus making it possible to prevent inadvertent blockage of electronic mail from a target.

Further, whether or not the expiration date is automatically updated can be set for each connection identification indicator. Therefore, a necessity for automatic update of the expiration date can be decided depending on a relationship with a target or a purpose. For this reason, it is also possible to control the acceptance or rejection of electronic mail by simple operation in a more thoughtful manner.

The mail server device according to the eighth invention as claimed in the present application is a mail server device used in the electronic mail communication system according to any one of the first to the third or the fifth to the seventh invention as claimed in the present application.

Therefore, use of the mail server device in the electronic mail communication system makes it possible to provide effects similar to those obtained in the first to the third or the fifth to the seventh invention.

The mail transmitting/receiving device according to the ninth invention as claimed in the present application is a mail transmitting/receiving device used in the electronic mail communication sys tem according to the fourth invention as claimed in the present application.

Therefore, use of the mail transmitting/receiving device in the electronic mail communication system makes it possible to provide effects similar to those obtained in the fourth invention.

The program according to the tenth invention as claimed in the present application is a program for allowing a computer to function as the transfer processing portion of the mail server device according to the eighth invention as claimed in the present application or as the mail processing portion of the mail transmitting/receiving device according to the ninth invention.

Therefore, the program is executed by the computer, thereby providing the effects similar to those obtained in the eighth or the ninth invention.

The record medium according to the eleventh invention as claimed in the present application is a record medium which stores a program according to the tenth invention as claimed in the present application.

Therefore, the program stored in the record medium is executed by the computer, thereby providing effects similar to those obtained in the tenth invention.

Further, the method for electronic mail communication according to the twelfth invention as claimed in the present application is a method for electronic mail communication in which an electronic mail communication system is provided with a plurality of mail transmitting/receiving devices, each of which is provided with a mail processing portion having functions to transmit and receive electronic mail and a computer capable of communicating with the mail transmitting/receiving device via information communication means, that is, a computer which includes a database which stores a target actual address which is an electronic mail address of a target for transmitting electronic mail and a user actual address which is an electronic mail address of a registered user for receiving electronic mail replied from the target in association with a connection identification indicator corresponding to a connection address which is a temporary electronic mail address of the registered user and an electronic mail address under control of the computer, and the electronic mail communication system is used to execute transfer processing of electronic mail based on data stored in the database, and the method for electronic mail communication which includes a mail receiving step in which the computer receives electronic mail from the mail transmitting/receiving device via the information communication means, a mail determination step in which the computer determines whether the electronic mail received in the mail receiving step is target addressed mail which is to be transmitted to a target from a registered user or user addressed mail which is to be transmitted from the target to the registered user based on header information of the electronic mail, a decode step in which where the electronic mail is determined to be the target addressed mail in the mail determination step, the computer generates target addressed transfer mail which is electronic mail in which a field value of the destination header which indicates a destination of the target addressed mail is given as a target actual address and a field value of the source header indicating a source is given as a connection address corresponding to the connection identification indicator, an encode step in which where the electronic mail is determined to be user addressed mail in the mail determination step, the computer generates user addressed transfer mail which is electronic mail in which a field value of the destination header of the user addressed mail is given as a user actual address, that is, user addressed transfer mail which is given as the target addressed mail when a text of the user addressed transfer mail is rewritten and replied in the mail transmitting/receiving device which has received the user addressed transfer mail, and a mail transmission step in which the computer transmits the electronic mail generated in the decode step or in the encode step via the information communication means according to the header information of the electronic mail.

Therefore, the method is used by the computer and the mail transmitting/receiving device, thereby providing effects similar to those acquired in the first invention.

Description has been made of the preferred embodiments of the present invention. The terminology employed herein is for the purpose of illustration but not of limitation. It should be understood that many changes and modification can be made within the scope of the appended claims without departing from the scope and spirit of the present invention. Also, while only typical embodiments have been described in detail, it will be understood by those skilled in the art that various modifications may be made therein without departing from the novel teaching and advantages of the present invention. Thus, such modifications are all included in the scope of the present invention. 

What is claimed is:
 1. An electronic mail communication system: comprising; a plurality of mail transmitting/receiving devices, each of which has a mail processing portion with functions to transmit and receive electronic mail; and a mail server device which is capable of communicating with the mail transmitting/receiving device via information communication means, wherein the mail server device is provided with a database which stores a target actual address which is an electronic mail address of a target for transmitting electronic mail and a user actual address which is an electronic mail address of a registered user for receiving electronic mail replied from the target in association with a connection identification indicator corresponding to a connection address which is a temporary electronic mail address of the registered user and an electronic mail address under the control of the mail server device and a transfer processing portion which executes transfer processing of electronic mail based on data stored in the database, and the transfer processing portion is provided with mail receiving means which receives electronic mail from the mail transmitting/receiving device via the information communication means, mail determination means which determines whether the electronic mail received in the mail receiving means is target addressed mail to be transmitted from the registered user to the target or user addressed mail to be transmitted from the target to the registered user based on header information of the electronic mail, decode means which generates target addressed transfer mail which is electronic mail in which a field value of a destination header indicating a destination of the target addressed mail is given as the target actual address, a field value of a source header indicating a source is given as a connection address corresponding to the connection identification indicator where the mail determination means determines that the electronic mail is the target addressed mail, encode means which generates user addressed transfer mail which is electronic mail in which a field value of a destination header of the user addressed mail is given as the user actual address, that is, user addressed transfer mail in which a text of the user addressed transfer mail is rewritten in the mail transmitting/receiving device which has received the user addressed transfer mail and replied to give the target addressed mail, where the mail determination means determines that the electronic mail is the user addressed mail, and mail transmitting means which transmits the electronic mail generated in the decode means or the encode means via the information communication means according to header information of the electronic mail.
 2. The electronic mail communication system according to claim 1, wherein the encode means is arranged in such a manner that a field value of the source header of the user addressed transfer mail is given as the connection address.
 3. The electronic mail communication system according to claim 1, wherein the mail determination means is further arranged so as to determine whether or not the electronic mail received by the mail receiving means is connection issuance requesting mail in which a registered user identifies the target actual address to request the mail server device for issuing a connection identification indicator based on header information of the electronic mail, the transfer processing portion is further provided with connection generation means in which where the mail determination means determines that the electronic mail is connection issuance requesting mail, a new connection identification indicator is issued and target actual address identified by the connection issuance requesting mail and the user actual address identified by the connection issuance requesting mail or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is generated template mail which is electronic mail having the user actual address written as a field value of the destination header and template mail which is given as the target addressed mail when a text of the template mail is rewritten and replied in the mail transmitting/receiving device which has received the template mail, and the mail transmitting means is further arranged so as to transmit the electronic mail generated by the connection generation means via the information communication means according to the header information of the electronic mail.
 4. The electronic mail communication system according to claim 3, wherein the mail processing portion of the mail transmitting/receiving device is further provided with connection issuance requesting means in which upon input of a signal which identifies the target actual address to request issuance of the connection identification indicator, the connection issuance requesting mail is generated and transmitted to the mail server device via the information communication means, and transmitting/receiving device-side connection issuance/target addressed mail generating means in which, upon input of a signal which identifies the target actual address and data to-be-transmitted to request issuance of the connection identification indicator and generation of target addressed mail, a signal which identifies the target actual address to request issuance of the connection identification indicator is input into the connection issuance requesting means, the template mail generated and transmitted by the mail server device based on the connection issuance requesting mail generated and transmitted by the connection issuance requesting means is received, and a text of the thus received template mail is rewritten into the data to-be-transmitted and replied.
 5. The electronic mail communication system according to claim 1, wherein the transfer processing portion is further provided with connection generation/decode means in which a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted is received from the mail transmitting/receiving device of a registered user via the information communication means to issue a new connection identification indicator, the target actual address identified by the requesting signal and the user actual address identified by the requesting signal or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is further generated electronic mail in which a field value of the destination header is given as the target actual address, a field value of the source header is given as a connection address corresponding to the new connection identification indicator and a text is given as the data to-be-transmitted, and the mail transmitting means is further arranged in such a manner that the electronic mail generated by the connection generation/decode means is transmitted via the information communication means according to the header information of the electronic mail.
 6. The electronic mail communication system according to claim 1, wherein the database further stores an expiration date of the connection identification indicator set for each connection identification indicator, and the transfer processing portion is further provided with validity determination means in which where the mail determination means determines that the electronic mail is the user addressed mail, determination is made for whether or not an expiration date of the connection identification indicator corresponding to the user addressed mail has expired based on the data stored in the database, and where the expiration date is determined not to have expired, control of the user addressed mail is shifted to the encode means, and error mail transmitting means in which where the validity determination means determines that the expiration date has expired, electronic mail to the effect that the user addressed mail has been erroneously transmitted is transmitted to a source of the user addressed mail.
 7. The electronic mail communication system according to claim 6, wherein the database further stores information on whether or not the expiration date of the connection identification indicator set for each connection identification indicator is automatically updated, and the transfer processing portion is further provided with expiration date update means in which where the mail determination means determines that the electronic mail is the target addressed mail, determination is made for whether or not the expiration date of the connection identification indicator corresponding to the target addressed mail is automatically updated based on the data stored in the database, where the expiration date is determined to be updated, the expiration date of the connection identification indicator stored in the database is updated, and where the expiration date is determined not to be updated, the expiration date of the connection identification indicator stored in the database is not updated.
 8. The mail server device which is used in the electronic mail communication system according to claim
 1. 9. The mail transmitting/receiving device which is used in the electronic mail communication system according to claim
 4. 10. A program which allows a computer to function as the transfer processing portion of the mail server device according to claim
 8. 11. A record medium which stores the program according to claim
 10. 12. A method for electronic mail communication, wherein an electronic mail communication system is provided with a plurality of mail transmitting/receiving devices, each of which is provided with a mail processing portion having functions to transmit and receive electronic mail; and a computer capable of communicating with the mail transmitting/receiving device via information communication means and a computer which includes a database which stores a target actual address which is an electronic mail address of a target for transmitting electronic mail and a user actual address which is an electronic mail address of a registered user for receiving electronic mail replied from the target in association with a connection identification indicator which corresponds to a connection address which is a temporary electronic mail address of the registered user, that is, an electronic mail address under control of the computer, and the electronic mail communication system is used to execute transfer processing of electronic mail based on data stored in the database, and the method for electronic mail communication: comprising; a mail receiving step in which the computer receives electronic mail from the mail transmitting/receiving device via the information communication means, a mail determination step in which determination is made by the computer for whether the electronic mail received in the mail receiving step is target addressed mail to be transmitted to a target from a registered user or user addressed mail to be transmitted from the target to the registered user based on header information of the electronic mail, a decode step in which where the electronic mail is determined to be the target addressed mail in the mail determination step, the computer generates target addressed transfer mail which is electronic mail in which a field value of the destination header indicating a destination of the target addressed mail is given as the target actual address and a field value of the source header indicating a source is given as a connection address corresponding to the connection identification indicator, an encode step in which where the electronic mail is determined to be user addressed mail in the mail determination step, the computer generates user addressed transfer mail which is electronic mail in which a field value of the destination header of the user addressed mail is given as the user actual address, that is, user addressed transfer mail which is given as the target addressed mail when a text of the user addressed transfer mail is rewritten and replied in the mail transmitting/receiving device which has received the user addressed transfer mail, and a mail transmission step in which the computer transmits the electronic mail generated in the decode step or in the encode step via the information communication means according to header information of the electronic mail.
 13. The electronic mail communication system according to claim 2, wherein the mail determination means is further arranged so as to determine whether or not the electronic mail received by the mail receiving means is connection issuance requesting mail in which a registered user identifies the target actual address to request the mail server device for issuing a connection identification indicator based on header information of the electronic mail, the transfer processing portion is further provided with connection generation means in which where the mail determination means determines that the electronic mail is connection issuance requesting mail, a new connection identification indicator is issued and target actual address identified by the connection issuance requesting mail and the user actual address identified by the connection issuance requesting mail or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is generated template mail which is electronic mail having the user actual address written as a field value of the destination header and template mail which is given as the target addressed mail when a text of the template mail is rewritten and replied in the mail transmitting/receiving device which has received the template mail, and the mail transmitting means is further arranged so as to transmit the electronic mail generated by the connection generation means via the information communication means according to the header information of the electronic mail.
 14. The electronic mail communication system according to claim 13, wherein the mail processing portion of the mail transmitting/receiving device is further provided with connection issuance requesting means in which upon input of a signal which identifies the target actual address to request issuance of the connection identification indicator, the connection issuance requesting mail is generated and transmitted to the mail server device via the information communication means, and transmitting/receiving device-side connection issuance/target addressed mail generating means in which, upon input of a signal which identifies the target actual address and data to-be-transmitted to request issuance of the connection identification indicator and generation of target addressed mail, a signal which identifies the target actual address to request issuance of the connection identification indicator is input into the connection issuance requesting means, the template mail generated and transmitted by the mail server device based on the connection issuance requesting mail generated and transmitted by the connection issuance requesting means is received, and a text of the thus received template mail is rewritten into the data to-be-transmitted and replied.
 15. The electronic mail communication system according to claim 2, wherein the transfer processing portion is further provided with connection generation/decode means in which a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted is received from the mail transmitting/receiving device of a registered user via the information communication means to issue a new connection identification indicator, the target actual address identified by the requesting signal and the user actual address identified by the requesting signal or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is further generated electronic mail in which a field value of the destination header is given as the target actual address, a field value of the source header is given as a connection address corresponding to the new connection identification indicator and a text is given as the data to-be-transmitted, and the mail transmitting means is further arranged in such a manner that the electronic mail generated by the connection generation/decode means is transmitted via the information communication means according to the header information of the electronic mail.
 16. The electronic mail communication system according to claim 3, wherein the transfer processing portion is further provided with connection generation/decode means in which a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted is received from the mail transmitting/receiving device of a registered user via the information communication means to issue a new connection identification indicator, the target actual address identified by the requesting signal and the user actual address identified by the requesting signal or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is further generated electronic mail in which a field value of the destination header is given as the target actual address, a field value of the source header is given as a connection address corresponding to the new connection identification indicator and a text is given as the data to-be-transmitted, and the mail transmitting means is further arranged in such a manner that the electronic mail generated by the connection generation/decode means is transmitted via the information communication means according to the header information of the electronic mail.
 17. The electronic mail communication system according to claim 13, wherein the transfer processing portion is further provided with connection generation/decode means in which a connection issuance/target addressed transfer mail generation requesting signal which identifies the target actual address and data to-be-transmitted is received from the mail transmitting/receiving device of a registered user via the information communication means to issue a new connection identification indicator, the target actual address identified by the requesting signal and the user actual address identified by the requesting signal or data stored in advance in the database are stored in the database in association with the new connection identification indicator, and there is further generated electronic mail in which a field value of the destination header is given as the target actual address, a field value of the source header is given as a connection address corresponding to the new connection identification indicator and a text is given as the data to-be-transmitted, and the mail transmitting means is further arranged in such a manner that the electronic mail generated by the connection generation/decode means is transmitted via the information communication means according to the header information of the electronic mail.
 18. The electronic mail communication system according to claim 2, wherein the database further stores an expiration date of the connection identification indicator set for each connection identification indicator, and the transfer processing portion is further provided with validity determination means in which where the mail determination means determines that the electronic mail is the user addressed mail, determination is made for whether or not an expiration date of the connection identification indicator corresponding to the user addressed mail has expired based on the data stored in the database, and where the expiration date is determined not to have expired, control of the user addressed mail is shifted to the encode means, and error mail transmitting means in which where the validity determination means determines that the expiration date has expired, electronic mail to the effect that the user addressed mail has been erroneously transmitted is transmitted to a source of the user addressed mail.
 19. A program which allows a computer to function as the mail processing portion of the mail transmitting/receiving device according to claim
 9. 20. A record medium which stores the program according to claim
 19. 